EMS Abstracts

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EMS for Sport Recovery

  • Active Versus Passive Recovery in the 72 Hours After a 5-km Race

    Author Andy Bosak
    Abstract We do not clearly understand what type and duration of recovery works best after a hard run to restore the body to peak racing condition. This study compared 72 hr of active recovery after a 5-km running performance with 72 hr of passive recovery. A sample of 9 male and 3 female runners of above-average ability completed 3 trials within 6 days. Each 5-km trial was followed by 72 hr of passive recovery (PAS) or 72 hr of active recovery (ACT), a counterbalanced protocol. The 2 initial 5-km trials constituted separate PAS and ACT baselines. Mean finishing times did not differ significantly (p = 0.17) between ACT (19:35 + 1.5 min) and baseline (19:41 + 1.7 min); nor was there significant difference (p = 0.21) between PAS (19:30 + 1.5 min) and baseline (19:34 + 1.6 min). Average heart rate for PAS (177.9 + 6.3 b/min) was significantly higher (p = 0.04) than baseline (175.4 + 6.5 b/min), but ACT average heart rate (175.9 + 6.6 b/min) was significantly lower (p = 0.02) than baseline (178.9 + 6.4 b/min). For PAS, perceived rate of exertion at ending (19.8 + 0.6) was significantly greater (p = 0.01) than baseline (19.3 + 0.9), yet for ACT, perceived rate of exertion at ending (19.6 + 0.8) did not differ significantly (p = 0.17) from baseline (19.7 + 0.7). During PAS trials, 2 individuals ran a mean 12.0 + 2.8 s slower, 2 individuals ran a mean 33.0 + 21.0 s faster, and 8 individuals ran within 5.1 + 2.5 s of their first run. During the ACT trials, 1 participant ran 13.0 s slower, 3 participants ran a mean of 34.7 + 13.5 s faster, and 8 nonresponders ran within 5.5 + 2.7 s of baseline. Results indicate that 72 hr of passive and active recovery result in similar mean 5-km performance.
    Website Title The Sport Journal
    Website Type Quarterly Refereed
    Date 2008 summer
    URL http://www.thesportjournal.org/article/active-versus-passive-recovery-72-hours-after-5-km-race

    Attachments

    • Active Versus Passive Recov....pdf
    • Active Versus Passive Recovery in the 72 Hours After a 5-km Race | The Sport Journal
  • Comparison of swim recovery and muscle stimulation on lactate removal after sprint swimming

    Author Francis B Neric
    Author William C Beam
    Author Lee E Brown
    Author Lenny D Wiersma
    Abstract Competitive swimming requires multiple bouts of high-intensity exercise, leading to elevated blood lactate. Active exercise recovery has been shown to lower lactate faster than passive resting recovery but may not always be practical. An alternative treatment, electrical muscle stimulation, may have benefits similar to active recovery in lowering blood lactate but to date is unstudied. Therefore, this study compared submaximal swimming and electrical muscle stimulation in reducing blood lactate after sprint swimming. Thirty competitive swimmers (19 men and 11 women) participated in the study. Each subject completed 3 testing sessions consisting of a warm-up swim, a 200-yard maximal frontcrawl sprint, and 1 of 3 20-minute recovery treatments administered in random order. The recovery treatments consisted of a passive resting recovery, a submaximal swimming recovery, or electrical muscle stimulation. Blood lactate was tested at baseline, after the 200-yard sprint, and after 10 and 20 minutes of recovery. A significant interaction (p < 0.05) between recovery treatment and recovery time was observed. Blood lactate levels for the swimming recovery were significantly lower at 10 minutes (3.50 +/- 1.57 mmol.L-1) and 20 minutes (1.60 +/- 0.57 mmol.L-1) of recovery than either of the other 2 treatments. Electrical muscle stimulation led to a lower mean blood lactate (3.12 +/- 1.41 mmol.L-1) after 20 minutes of recovery compared with passive rest (4.11 +/- 1.35 mmol.L-1). Submaximal swimming proved to be most effective at lowering blood lactate, but electrical muscle stimulation also reduced blood lactate 20 minutes postexercise significantly better than resting passive recovery. Electrical muscle stimulation shows promise as an alternate recovery treatment for the purpose of lowering blood lactate.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Dec 2009
    URL http://www.ncbi.nlm.nih.gov/pubmed/19910818

    Attachments

    • Comparison of Swim Recovery and Muscle Stimulation on Lactate Removal After Sprint Swimming.pdf
  • Does Sports Massage Contribute to Post-Workout Recovery?

    Author Ross Turchaninov
    Author Boris Prilutsky
    Author Oleg Bouimer
    Abstract According to the authors, there are four important guidelines to follow when giving sports massage. Many studies into the effectiveness of massage came to the conclusion that massage is not effective, but they were not following one or more of the guidelines. The guidelines are: (1) wait 2-2.5 hours from the end of exercise; (2) 30-40 minutes to one hour of massage; (3) kneading of affected muscles for 50% of the time; (4) apply significant pressure, below pain threshold.
    URL http://www.massagevideonetwork.com/sports_massage_and_recovery.doc

    Attachments

    • Gmail - [Supertraining] DOMS - Delayed Onset of Muscle Soreness - giovanni.ciriani@gmail.com
    • sports_massage_and_recovery.doc
  • DOMS

    Author J Sankoff
    Abstract Summary of what DOMS is; lacks mention of EMS.
    Publication Triathlete
    Date Nov 2007

    Attachments

    • Triathlete Nov07 DOMS.pdf
  • Effectiveness of active versus passive recovery strategies after futsal games

    Author Antonio Tessitore
    Author Romain Meeusen
    Author Rita Pagano
    Author Cinzia Benvenuti
    Author Monica Tiberi
    Author Laura Capranica
    Abstract This study aimed to investigate the effects of immediate postgame recovery interventions (seated rest, supine electrostimulation, low-intensity land exercises, and water exercises) on anaerobic performance (countermovement jump [CMJ], bounce jumping, 10-m sprint), hormones (salivary cortisol, urinary catecholamines), and subjective ratings (rate of perceived exertion [RPE], leg muscle pain, Questionnaire of Recovery Stress for Athletes [RestQ Sport], 10-point Likert scale), and hours of sleep of futsal players. Heart rate (HR), blood lactate, and RPE were used to evaluate the intensity of 4 futsal games in 10 players using a crossover design (P < 0.05), randomly allocating athletes to 1 of the 4 recovery interventions at the end of each game. No significant difference emerged between HR, blood lactate, RPE, and level of hydration of the games. A significant difference (P < 0.001) between games emerged for total urinary catecholamines, with an increase from the first to the second game and a gradual reduction up to the fourth game. After the game, significant reductions in CMJ (P < 0.001) and 10-m sprints (P < 0.05) emerged. No significant difference was found between recovery interventions for anaerobic performances, hormones, muscle pain, and RestQ Sport. Even though a well-balanced diet, rehydration, and controlled lifestyle might represent a sufficient recovery intervention in young elite athletes, the players perceived significantly increased benefit (P < 0.01) from the electrostimulation (7.8 +/- 1.4 points) and water exercises (7.6 +/- 2.1 points) compared to dry exercises (6.6 +/- 1.8 points) and seated rest (5.2 +/- 0.8 points.), which might improve their attitude toward playing. To induce progressive hormonal adaptation to the high exercise load of multiple games, in the last 2 weeks of the preseason, coaches should organize friendly games at a level similar to that of the competitive season.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Sep 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/18714251

    Tags:

    • Adult
    • Anaerobic Threshold
    • Analysis of Variance
    • Anthropometry
    • Catecholamines
    • Chi-Square Distribution
    • Cross-Over Studies
    • Dehydration
    • Electric Stimulation
    • Heart Rate
    • Humans
    • Hydrocortisone
    • Lactates
    • Male
    • Physical Education and Training
    • Physical Exertion
    • Physical Fitness
    • Questionnaires
    • Recovery of Function
    • Rest
    • Saliva
    • Sleep
    • Soccer
    • Supine Position

    Attachments

    • Effectiveness of Active Recovery after Futsal.pdf
    • PubMed Snapshot
  • Effects of different recovery interventions on anaerobic performances following preseason soccer training

    Author Antonio Tessitore
    Author Romain Meeusen
    Author Cristina Cortis
    Author Laura Capranica
    Abstract In the preseason soccer training, morning and afternoon training sessions often are scheduled daily. The high frequency of training sessions could place heavy strain on biological systems, and it is necessary to apply proper recovery strategies for improving the players&apos; capability to regain an adequate working state for subsequent training units. However, the effect of recovery interventions following soccer training units is debatable, due to a lack of studies performed in field situations. The aim of this study was to examine, during a 21-day preseason soccer training, the most effective recovery intervention (i.e., passive, dry-aerobic exercises, water-aerobic exercises, electrostimulation) on anaerobic performances (i.e., squat jump, countermovement jump, bounce jumping, and 10-m sprint) and subjective ratings (i.e., perceived exertion and muscle pain), with the conditions before the intervention controlled and standardized. Twelve young (age: 18.1 +/- 1.2 years) elite soccer players participated. Data were collected on 4 occasions 2 days apart and at the same time of the day. Activity and dietary intake were replicated on each occasion. After baseline measurements, participants performed a standardized training during which their heart rates and ratings of perceived exertion were recorded. This was followed by a 20-minute recovery intervention. After a 5-hour rest, athletes&apos; ratings of muscle pain were recorded prior to a second test session. There were no significant differences in exercise intensities and baseline anaerobic performances. Significantly (p < 0.01) better performances were observed in the afternoon. Although no main effect of recovery intervention was observed on anaerobic performances, dry-aerobic exercises (0.6 +/- 0.9) and electrostimulation (0.6 +/- 1.2) were more beneficial (p < 0.01) than water-aerobic exercises (2.1 +/- 1.1) and passive rest (2.1 +/- 1.7) for reducing muscle pain, which could affect the player&apos;s working ability.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Aug 2007
    URL http://www.ncbi.nlm.nih.gov/pubmed/17685701

    Tags:

    • Adolescent
    • Adult
    • Anaerobic Threshold
    • Analysis of Variance
    • Cross-Over Studies
    • Humans
    • Male
    • Physical Education and Training
    • Physical Fitness
    • Recovery of Function
    • Soccer

    Attachments

    • EFFECTS OF DIFFERENT RECOVERY INTERVENTIONS ON ANAEROBIC PERFORMANCES FOLLOWING PRESEASON SOCCER TRAINING.pdf
    • PubMed Snapshot
  • Fatigue and recovery after high-intensity exercise part I: neuromuscular fatigue

    Author G Lattier
    Author G Y Millet
    Author A Martin
    Author V Martin
    Abstract The contribution of central and peripheral factors to muscle fatigue were quantified following a high-intensity uphill running exercise. Eight male volunteers performed an intermittent exercise at 120 % of maximal aerobic speed on a treadmill with an 18 % grade. Electrically evoked and voluntary contractions of the knee extensors and EMG of the two vastii were analyzed before and immediately after the high-intensity exercise. Isometric maximal voluntary contraction decreased slightly (-7+/-8 %; p < 0.05) after exercise but no changes were found in the level of maximal activation or in the torque produced by a 80 Hz maximal stimulation applied to the femoral nerve. Following exercise, the single twitch was characterized by lower peak torque, maximal rate of force development, and relaxation (-28+/-11%, -25+/-12%, -31+/-15% respectively, p < 0.001), and higher surface of the M-wave for both vastii. The ratio between the torques evoked by 20 Hz and 80 Hz stimulation declined significantly (-22+/-10%, p < 0.01) after exercise. These findings indicate that muscle fatigue after high-intensity running exercise is due to significant alteration in excitation-contraction coupling and that this type of exercise does not induce significant central fatigue or changes at the crossbridge level.
    Publication International Journal of Sports Medicine
    Date Aug 2004
    URL http://www.ncbi.nlm.nih.gov/pubmed/15346234

    Tags:

    • Adult
    • Electric Stimulation
    • Exercise
    • Humans
    • Hydrogen-Ion Concentration
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Nervous System
    • Physical Endurance

    Attachments

    • Fatigue and recovery after high-intensity exercise part 1 neuromuscular fatigue.pdf
    • PubMed Snapshot
  • Fatigue and recovery after high-intensity exercise. Part II: Recovery interventions

    Author G Lattier
    Author G Y Millet
    Author A Martin
    Author V Martin
    Abstract The purpose of this study was to determine the effect of three types of recovery intervention to neuromuscular function after high-intensity uphill running exercise. The 20-min recovery interventions were (i) passive, (ii) active (running at 50 % of maximal aerobic speed), and (iii) low-frequency electromyostimulation. Evoked twitch and maximal voluntary contractions of knee extensor muscles (KE) and EMG of the vastus lateralis and vastus medialis were analysed immediately after the exercise, 10 min after the end of the recovery periods, and 65 min after the exercise (Post65). An all-out running test was also performed 80 min after the end of the fatiguing exercise. No significant differences were noted in any measured parameters but a tendency to a better performance during the all-out test was found after the electromyostimulation intervention (297.5 +/- 152.4 s vs. 253.6 +/- 117.1 s and 260.3 +/- 105.8 s after active and passive recovery, p = 0.13 and p = 0.12, respectively). At Post65, isometric maximal voluntary contraction torque did not return to the pre-exercise values (279.7 +/- 86.5 vs. 298.7 +/- 92.6 Nm, respectively; p < 0.05). During recovery, electrically evoked twitch was characterized by an increase of peak torque, maximal rate of force development and relaxation (+ 24 - 33 %; p < 0.001) but these values were still lower at Post65 than pre-exercise. Amplitude and surface of the M-wave decreased during recovery. These results show that the recovery of the voluntary force-generating capacity of KE after an intermittent high-intensity uphill running exercise do not depend on the type of recovery intervention tested here. It can also be concluded that the recovery of twitch contractile properties does not necessarily follow that of maximal muscle strength.
    Publication International Journal of Sports Medicine
    Date Oct 2004
    URL http://www.ncbi.nlm.nih.gov/pubmed/15459831

    Tags:

    • Adult
    • Electric Stimulation Therapy
    • Electromyography
    • Humans
    • Knee
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Physical Endurance
    • Running
    • Torque

    Attachments

    • Fatigue and recovery after high-intensity exercise part 2 recovery interventions.pdf
    • PubMed Snapshot
  • Improved function from progressive strengthening interventions after total knee arthroplasty: a randomized clinical trial with an imbedded prospective cohort

    Author Stephanie C Petterson
    Author Ryan L Mizner
    Author Jennifer E Stevens
    Author Leo Raisis
    Author Alex Bodenstab
    Author William Newcomb
    Author Lynn Snyder-Mackler
    Abstract OBJECTIVE: To determine the effectiveness of progressive quadriceps strengthening with or without neuromuscular electrical stimulation (NMES) on quadriceps strength, activation, and functional recovery after total knee arthroplasty (TKA), and to compare progressive strengthening with conventional rehabilitation. METHODS: A randomized controlled trial was conducted between July 2000 and November 2005 in an academic outpatient physical therapy clinic. Two hundred patients who had undergone primary, unilateral TKA for knee osteoarthritis were randomized to 1 of 2 interventions 4 weeks after surgery, and 41 patients eligible for enrollment who did not participate in the intervention were tested 12 months after surgery (standard of care group). All randomized patients received 6 weeks of outpatient physical therapy 2 or 3 times per week through 1 of 2 intervention protocols: an exercise group (volitional strength training) or an exercise-NMES group (volitional strength training and NMES). Treatment effects were evaluated by a burst superimposition test to assess quadriceps strength and volitional activation 3 and 12 months postoperatively. The Medical Outcomes Study Short Form 36 and Knee Outcome Survey were completed. Knee range of motion, Timed Up and Go, Stair-Climbing Test, and 6-Minute Walk were also measured. RESULTS: Strength, activation, and function were similar between the exercise and exercise-NMES groups at 3 and 12 months. The standard of care group was weaker and exhibited worse function at 12 months compared with both treatment groups. CONCLUSION: Progressive quadriceps strengthening with or without NMES enhances clinical improvement after TKA, achieving similar short- and long-term functional recovery and approaching the functional level of healthy older adults. Conventional rehabilitation does not yield similar outcomes.
    Publication Arthritis and Rheumatism
    Date Feb 15, 2009
    URL http://www.ncbi.nlm.nih.gov/pubmed/19177542

    Attachments

    • Improved function from progressive strengthening - Athritis care Research 2009.pdf
    • PubMed Snapshot
  • Neuromuscular fatigue and recovery in elite female soccer: effects of active recovery

    Author Helena Andersson
    Author Truls Raastad
    Author Johnny Nilsson
    Author Gøran Paulsen
    Author Ina Garthe
    Author Fawzi Kadi
    Abstract PURPOSE: To investigate the time course of recovery from neuromuscular fatigue and some biochemical changes between two female soccer matches separated by an active or passive recovery regime. METHODS: Countermovement jump (CMJ), sprint performance, maximal isokinetic knee flexion and extension, creatine kinase (CK), urea, uric acid, and perceived muscle soreness were measured in 17 elite female soccer players before, immediately after, 5, 21, 45, 51, and 69 h after a first match, and immediately after a second match. Eight players performed active recovery (submaximal cycling at 60% of HRpeak and low-intensity resistance training at < 50% 1RM) 22 and 46 h after the first match. RESULTS: In response to the first match, a significant decrease in sprint performance (-3.0 +/- 0.5%), CMJ (-4.4 +/- 0.8%), peak torque in knee extension (-7.1 +/- 1.9%) and flexion (-9.4 +/- 1.8%), and an increase in CK (+ 152 +/- 28%), urea (15 +/- 2), uric acid (+ 11 +/- 2%), and muscle soreness occurred. Sprint ability was first to return to baseline (5 h) followed by urea and uric acid (21 h), isokinetic knee extension (27 h) and flexion (51 h), CK, and muscle soreness (69 h), whereas CMJ was still reduced at the beginning of the second match. There were no significant differences in the recovery pattern between the active and passive recovery groups. The magnitude of the neuromuscular and biochemical changes after the second match was similar to that observed after the first match. CONCLUSION: The present study reveals differences in the recovery pattern of the various neuromuscular and biochemical parameters in response to a female soccer match. The active recovery had no effects on the recovery pattern of the four neuromuscular and three biochemical parameters.
    Publication Medicine and Science in Sports and Exercise
    Date Feb 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/18202563

    Tags:

    • Adaptation, Physiological
    • Adolescent
    • Adult
    • Creatine Kinase
    • Exercise Test
    • Female
    • Humans
    • Muscle Fatigue
    • Norway
    • Pain Measurement
    • Physical Exertion
    • Soccer
    • Sweden
    • Urea
    • Uric Acid

    Attachments

    • PubMed Snapshot
  • Recovery from training: a brief review.

    Author Phillip A Bishop
    Author Eric Jones
    Author A Krista Woods
    Abstract Athletes spend a much greater proportion of their time recovering than they do in training. Yet, much attention has been given to training with very little investigation of recovery. The purpose of this review is to stimulate further research into this vital area of training. Recovery can be categorized in three terms: i) immediate recovery between exertions; ii) short-term recovery between repeats (e.g., between resistance sets or interval bouts); and iii) training recovery between workouts. The focus of this review is training recovery. Full training recovery is essential to optimal performance and improvement. This review includes an examination of extant research on recovery and a very brief review of some potential modalities and techniques for hastening recovery and the time course of recovery and responses to some treatments. Measures of recovery and practical considerations are discussed briefly. Much research is needed in this area, but there are obstacles to high quality research. Attention must be given to key issues in research on recovery, especially the individual response to recovery treatments.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date May 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/18438210

    Tags:

    • Adolescent
    • Adult
    • Athletic Performance
    • Female
    • Humans
    • Male
    • Muscle Fatigue
    • Physical Education and Training
    • Physical Endurance
    • Physical Exertion
    • Recovery of Function
    • Rest
    • Sensitivity and Specificity
    • Sports
    • Time Factors

    Attachments

    • PubMed Snapshot
    • Recovery From TrainingReview.pdf
  • Skeletal muscle damage and repair

    Author Peter M. Tiidus
    Abstract Professionals and students interested in understanding the physiological mechanisms of skeletal muscle damage and repair will welcome this uniquely comprehensive text. Presenting both research-based information and applied clinical topics, Skeletal Muscle Damage and Repairassists readers in understanding the interrelationships of basic physiology, specific populations, and practical treatments for muscle injury and damage. The text covers a broad spectrum of topics:-The basic science and scientific methods used to investigate exercise-related muscle damage and repair-A review of current research related to the mechanisms of muscle damage, physiological responses to damage, and subsequent methods of muscle repair-An examination of issues specific to various populations, including the elderly, diabetics, people with muscular dystrophies, and elite athletes-An evaluation of other practical topics as they apply to muscle damage and repair, such as gender and hormonal influences, effects on gait mechanics, the impact in workplace settings, and the issue of "high-responder" individuals who seem extraordinarily susceptible to muscle damage-A critical analysis of the efficacy of various popular treatment modalities, including massage, ultrasound, trigger-point therapy, physical therapy, nutraceutical interventions, and hyperbaric oxygen treatment The text is organized into 21 chapters, each written by an internationally acclaimed researcher or research group who are experts in their field. Chapters are grouped into three parts covering a wide range of both current research and clinical topics related to skeletal muscle damage and repair mechanisms and their applications. Part Ipresents the physical mechanisms of muscle damage, inflammation, and repair. Part IIaddresses muscle damage and repair mechanisms and issues in specific populations, including older adults, diabetics, and athletes. Part IIIconsiders the influences of treatment interventions on muscle repair and healing. The combination of the three parts culminates in a thorough understanding of muscle damage and repair.Skeletal Muscle Damage and Repairpromotes an understanding of the physiological mechanisms of skeletal muscle damage and repair vital for many health professionals, therapists, kinesiologists, and physical educators. This comprehensive text exposes professionals, clinicians, and researchers to a range of issues related to muscle damage and repair. It also encourages communication between researchers interested in the mechanisms of muscle damage and repair and practitioners who treat muscle injury in various populations.
    Publisher Human Kinetics
    Date 2008
    # of Pages 337

    Attachments

    • Google Books Link
    • Skeletal muscle damage and repair - Google Books
  • The effects of athletic massage on delayed onset muscle soreness, creatine kinase, and neutrophil count: a preliminary report

    Author L L Smith
    Author M N Keating
    Author D Holbert
    Author D J Spratt
    Author M R McCammon
    Author S S Smith
    Author R G Israel
    Abstract It was hypothesized that athletic massage administered 2 hours after eccentric exercise would disrupt an initial crucial event in acute inflammation, the accumulation of neutrophils. This would result in a diminished inflammatory response and a concomitant reduction in delayed onset muscle soreness (DOMS) and serum creatine kinase (CK). Untrained males were randomly assigned to a massage (N = 7) or control (N = 7) group. All performed five sets of isokinetic eccentric exercise of the elbow flexors and extensors. Two hours after exercise, massage subjects received a 30-minute athletic massage; control subjects rested. Delayed onset muscle soreness and CK were assessed before exercise and at 8, 24, 48, 72, 96, and 120 hours after exercise. Circulating neutrophils were assessed before and immediately after exercise, and at 30-minute intervals for 8 hours; cortisol was assessed before and immediately after exercise, and at 30-minute intervals for 8 hours; cortisol was assessed at similar times. A trend analysis revealed a significant (p < 0.05) treatment by time interaction effect for 1) DOMS, with the massage group reporting reduced levels; 2) CK, with the massage group displaying reduced levels; 3) neutrophils, with the massage group displaying a prolonged elevation; and 4) cortisol, with the massage group showing a diminished diurnal reduction. The results of this study suggest that sports massage will reduce DOMS and CK when administered 2 hours after the termination of eccentric exercise. This may be due to a reduced emigration of neutrophils and/or higher levels of serum cortisol.
    Publication The Journal of Orthopaedic and Sports Physical Therapy
    Date Feb 1994
    URL http://www.ncbi.nlm.nih.gov/pubmed/8148868

    Tags:

    • Adult
    • Creatine Kinase
    • Exercise
    • Humans
    • Hydrocortisone
    • Isometric Contraction
    • Leukocyte Count
    • Male
    • Massage
    • Myositis
    • Neutrophils
    • Pain Measurement

    Attachments

    • The Effect of Athletic Massage of Delayed Onset Muscle Soreness.pdf


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EMS in General

  • Effects of stimulation intensity on the physiological responses of human motor units

    Author S A Binder-Macleod
    Author E E Halden
    Author K A Jungles
    Abstract Quadriceps femoris muscles were studied in 50 healthy subjects to determine the physiological responses of the motor units recruited at different force levels during transcutaneous electrical stimulation. During one set of experiments force-frequency relationships were compared at stimulation intensities that produced tetanic contraction of 20%, 50%, or 80% of the maximum voluntary isometric contraction (MVC). No differences in the normalized force-frequency relationship were observed between the 20% and 50% of MVC conditions and only a slight shift to the left was observed at 80% of MVC. The other set of experiments measured the responses to electrically elicited fatigue tests using frequencies of 20, 40, or 60 pps and, at each frequency, intensities that produced 20% or 50% of MVC. Fatigue was greater for the 50% than 20% MVC force conditions. Within each force level fatigue increased with increasing frequency. However, though the differences in the level of recruitment needed to produce the two forces varied for each frequency, the differences in the amount of fatigue produced at each force did not vary between the three stimulation frequencies. This suggests that the fatigue characteristics of the recruited motor units were similar at all intensities tested. We posit, therefore, that the physiological recruitment order during transcutaneous electrical stimulation is less orderly than previously suggested.
    Publication Medicine and Science in Sports and Exercise
    Date Apr 1995
    URL http://www.ncbi.nlm.nih.gov/pubmed/7791587

    Tags:

    • Adult
    • Electric Stimulation
    • Female
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Recruitment, Neurophysiological
    • Thigh

    Attachments

    • Effects of Stimulation Intensity on the Physiological responses of human motor units.pdf
    • PubMed Snapshot
  • Electrical stimulation as a modality to improve performance of the neuromuscular system

    Author Marc Vanderthommen
    Author Jacques Duchateau
    Abstract Transcutaneous neuromuscular electrical stimulation (NMES) can modify the order of motor unit recruitment and has a profound influence on the metabolic demand associated with producing a given muscle force. Because of these differences, interventions that combine NMES with voluntary contractions can provide beneficial outcomes for some individuals. The adaptations evoked by NMES are not confined to the activated muscle but also involve neural adaptations through reflex inputs to the spinal cord and supraspinal centers.
    Publication Exercise and Sport Sciences Reviews
    Date Oct 2007
    URL http://www.ncbi.nlm.nih.gov/pubmed/17921786

    Tags:

    • Athletic Performance
    • Belgium
    • Humans
    • Motor Activity
    • Muscle Contraction
    • Psychomotor Performance
    • Quadriceps Muscle
    • Transcutaneous Electric Nerve Stimulation

    Attachments

    • Electrical Stimulation as a Modality to Improve Performance of the Neuromuscular System.pdf
    • PubMed Snapshot
  • Electrical stimulation of quadriceps femoris in an elite weight lifter: a single subject experiment

    Author A Delitto
    Author M Brown
    Author M J Strube
    Author S J Rose
    Author R C Lehman
    Abstract The response to treatment of high intensity neuromuscular electrical stimulation (NMES) to both quadriceps femoris muscles as an adjunct to ongoing weight training was evaluated using a single subject experimental design. For an elite weight lifter weekly maximal measurements of snatch (S), clean and jerk (CJ), and front squat (SQ) were obtained over 4 months during which the subject weight trained daily for 3 h. The 1st month, baseline data were collected. After baseline measurements, a 1-month period of high-intensity NMES was added to the subject&apos;s weight training. NMES was then withdrawn for 1 month and administered once more for 2 weeks. Three quadriceps femoris muscle biopsies were taken, two during the initial baseline period and one just before the end of the first stimulation period. The results showed a significant and clear relationship between performance gains and NMES administration and withdrawal. Steep gains for S, CJ, and SQ were seen after 2 weeks of stimulation, with front squat showing a 20-kg increase within the 1st week of both stimulation periods. Muscle biopsy showed an increased type I fiber area, decreased type IIa and IIb fiber area, and an increase of type II fibers after NMES. The results of this study support the use of high-dose NMES as an adjunct to weight training in elite lifters.
    Publication International Journal of Sports Medicine
    Date Jun 1989
    URL http://www.ncbi.nlm.nih.gov/pubmed/2674035

    Tags:

    • Adult
    • Electric Stimulation
    • Humans
    • Male
    • Muscles
    • Physical Education and Training
    • Sports
    • Thigh
    • Weight Lifting

    Attachments

    • PubMed Snapshot
  • Electronic Muscle Stimulation in the Training Model

    Author Charlie Francis
    Abstract The author is one of the most knowledgeable speed coaches around, having used EMS for 30 years, and in the training of olympic athletes. His training techniques and tips are the best around for periodization. Some of the EMS concepts are outdated. The "electronic" rather than "electrical" in the title, reveals it is influenced by non-professional devices.
    Date 2008
    URL http://www.charliefrancis.com/store/Scripts/prodView.asp?
    idproduct=37

    Attachments

    • CharlieFrancis.com :: Online Store
  • Evaluation of the ability to make non-invasive estimation of muscle contractile properties on the basis of the muscle belly response

    Author R. Dahmane
    Author V. Valencic
    Author N. Knez
    Author I. Eržen
    Abstract Abstract The histochemical and biomechanical relationships of limb muscles are examined in two groups of 15 men aged between 17 and 40 years. Seven muscles are chosen: biceps brachii, triceps brachii (TB), flexor digitorum superficialis, extensor digitorum, biceps femoris, tibialis anterior and gastrocnemius caput mediale (GCM). The aim of the preliminary study is to evaluate an alternative method based on a tensiomyographic (TMG) non-invasive measurement technique. The percentage of type I muscle fibres obtained with the histochemical method is 2.2 times higher for the slowest measured muscle (GCM) than for the fastest (TB). The contraction time of a muscle belly twitch response measured by TMG is 1.9 times higher for GCM than for TB. Statistical analysis of the data obtained by tensiomyographic and histochemical techniques shows a significant correlation between the contraction time of muscle response measured by TMG and the percentage of type I muscle fibres (correlation coefficient equals 0.93). Results of the study suggest using the TMG measuring technique as a basis for the estimation of the percentage of type I muscle fibres.
    Publication Medical and Biological Engineering and Computing
    Date January 12, 2001
    URL http://dx.doi.org/10.1007/BF02345266

    Attachments

    • Evaluation of the ability to make non-invasive estimation of muscle contractile properties on the basis of the muscle-belly response.pdf
    • SpringerLink Snapshot
  • Force output and energy metabolism during neuromuscular electrical stimulation: a 31P-NMR study

    Author G O Matheson
    Author R J Dunlop
    Author D C McKenzie
    Author C F Smith
    Author P S Allen
    Abstract The purpose of this study was to determine the acute physiologic effects of two electrical stimulation protocols commonly used for muscle rehabilitation. Surface electrodes were used to provide 12 stimulations of the calf musculature. In protocol A the duty cycle was fixed at 1:1 (10-second stimulation: 10-second rest); for protocol B it was 1:5 (10-second stimulation: 50-second rest). We continuously recorded isometric plantarflexor force in six healthy male subjects during stimulation using a load cell connected to a foot pedal ergometer. Metabolic changes in the stimulated gastrocnemius muscle were monitored in the supine position using 31P-NMR spectroscopy (Phillips 1.5 tesla NMR machine). Relative changes in phosphocreatine (PCr), inorganic phosphate (Pi), and intracellular pH (pHi) were obtained during stimulation and recovery, using a 1.5 cm RF surface antenna. Over the 12 stimulations, protocol A produced a significantly (p < 0.001), greater force decline (protocol A: 30.4 +/- 1.3%, protocol B: 13 +/- 0.8%); a significantly (p < 0.005), greater increase in Pi/PCr (protocol A: 210%, protocol B: 50%); and a significantly (p <0.001), lower pHi (protocol A: 6.8 +/- 0.16, protocol B: 7.03 +/- 0.12). We conclude that the shorter duty cycle produces more fatigue throughout the stimulation period, possibly as a result of greater intracellular acidosis and reduced availability of the high energy phosphate PCr. The clinical application of this finding relates to the selection of a stimulation protocol that maximizes strength gains in atrophic vs healthy muscle.
    Publication Scandinavian Journal of Rehabilitation Medicine
    Date Sep 1997
    URL http://www.ncbi.nlm.nih.gov/pubmed/9271152

    Tags:

    • Adult
    • Clinical Protocols
    • Electric Stimulation Therapy
    • Energy Metabolism
    • Humans
    • Leg
    • Magnetic Resonance Spectroscopy
    • Male
    • Muscle, Skeletal
    • Muscular Atrophy
    • Phosphorus Radioisotopes

    Attachments

    • PubMed Snapshot
  • Force-frequency relationship and potentiation in mammalian skeletal muscle

    Author Brian R. MacIntosh
    Author Janine C. Willis
    Abstract Repetitive activation of a skeletal muscle results in potentiation of the twitch contractile response. Incompletely fused tetanic contractions similar to those evoked by voluntary activation may also be potentiated by prior activity. We aimed to investigate the role of stimulation frequency on the enhancement of unfused isometric contractions in rat medial gastrocnemius muscles in situ. Muscles set at optimal length were stimulated via the sciatic nerve with 50-{micro}s duration supramaximal pulses. Trials consisted of 8 s of repetitive trains [5 pulses (quintuplets) 2 times per second or 2 pulses (doublets) 5 times per second] at 20, 40, 50, 60, 70, and 80 Hz. These stimulation frequencies represent a range over which voluntary activation would be expected to occur. When the frequency of stimulation was 20, 50, or 70 Hz, the peak active force (highest tension during a contraction [-] rest tension) of doublet contractions increased from 2.2 {+/-} 0.2, 4.1 {+/-} 0.4, and 4.3 {+/-} 0.5 to 3.1 {+/-} 0.3, 5.6 {+/-} 0.4, and 6.1 {+/-} 0.7 N, respectively. Corresponding measurements for quintuplet contractions increased from 2.2 {+/-} 0.2, 6.1 {+/-} 0.5, and 8.7 {+/-} 0.7 to 3.2 {+/-} 0.3, 7.3 {+/-} 0.6, and 9.0 {+/-} 0.7 N, respectively. Initial peak active force values were 27 {+/-} 1 and 61.5 {+/-} 5% of the maximal (tetanic) force for doublet and quintuplet contractions, respectively, at 80 Hz. With doublets, peak active force increased at all stimulation frequencies. With quintuplets, peak active force increased significantly for frequencies up to 60 Hz. Twitch enhancement at the end of the 8 s of repetitive stimulation was the same regardless of the pattern of stimulation during the 8 s, and twitch peak active force returned to prestimulation values by 5 min. These experiments confirm that activity-dependent potentiation is evident during repeated, incompletely fused tetanic contractions over a broad range of frequencies. This observation suggests that, during voluntary motor unit recruitment, derecruitment or decreased firing frequency would be necessary to achieve a fixed (submaximal) target force during repeated isometric contractions over this time period.
    Publication J Appl Physiol
    Date June 1, 2000
    URL http://jap.physiology.org/cgi/content/abstract/88/6/2088

    Attachments

    • Force-frequency relationship and potentiation.pdf
    • HighWire Full Text PDF
    • HighWire Snapshot
  • Functional and biochemical properties of chronically stimulated human skeletal muscle

    Author Martin Nuhr
    Author Richard Crevenna
    Author Bärbel Gohlsch
    Author Christian Bittner
    Author Johannes Pleiner
    Author Günther Wiesinger
    Author Veronika Fialka-Moser
    Author Michael Quittan
    Author Dirk Pette
    Abstract The present study was undertaken to investigate in a randomized controlled trial the effects of chronic (10 weeks, 4 h per day, 7 days per week) low-frequency (15 Hz) stimulation (CLFS) of the knee extensor and hamstring muscles of both legs in healthy volunteers via surface electrodes. A control group (n=10) underwent the same treatment (sham stimulation) as the CLFS-treated group (n=10), except that stimulation intensity was kept at a level which did not evoke contractions. Biopsy samples were taken before the onset and after cessation of stimulation from the right vastus lateralis muscle of all subjects. The biopsy samples were analyzed for changes in myosin heavy chain (MHC) isoforms and activities of citrate synthase (CS) and glyceraldehyde phosphate dehydrogenase (GAPDH) as markers of aerobic-oxidative and anaerobic pathways of energy metabolism, respectively. In addition, functional properties, i.e., oxygen consumption (VO(2)) and work capacity, were assessed. Sham stimulation did not affect the functional properties and had no detectable effect on MHC isoform and enzyme activity patterns. Conversely, CLFS induced changes in the MHC isoform pattern in the fast-to-slow direction with an approximately 20% decrease in the relative concentration of MHCIId/x (from 28% to 22%) and an approximately 10% increase in the relative concentration of MHCI (from 30% to 34%). In addition, CLFS led to a approximately 9% increase in the activity of CS concomitant with an approximatley 7% decrease in the activity of GAPDH. This increase in aerobic-oxidative capacity was accompanied by improved work capacity and VO(2) at the anaerobic threshold by 26% and 20%, respectively.
    Publication European Journal of Applied Physiology
    Date Apr 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/12665986

    Tags:

    • Adult
    • Citrate (si)-Synthase
    • Electric Stimulation
    • Exercise Test
    • Glyceraldehyde-3-Phosphate Dehydrogenases
    • Humans
    • Male
    • Muscle, Skeletal
    • Myosin Heavy Chains
    • Oxygen Consumption
    • Time Factors

    Attachments

    • Nuhr-Pette-chronicstimhuman-Ejap2003.pdf
    • PubMed Snapshot
  • Inference of motor unit recruitment order in voluntary and electrically elicited contractions

    Author M. Knaflitz
    Author R. Merletti
    Author C. J. De Luca
    Publication J Appl Physiol
    Date April 1, 1990
    URL http://jap.physiology.org/cgi/content/abstract/68/4/1657

    Attachments

    • HighWire Snapshot
    • Inference of motor unit recruitment order in voluntary and electrically elicited contractions.pdf
  • Mapping of electrical muscle stimulation using MRI

    Author G R Adams
    Author R T Harris
    Author D Woodard
    Author G A Dudley
    Abstract The purpose of this study was to map the pattern of muscle contractile activity elicited by electromyostimulation (EMS). A secondary interest was to determine whether EMS evoked a different pattern of contractile activity than voluntary (VOL) efforts. These objectives were addressed by examining the pattern and extent of contrast shift in magnetic resonance (MR) images after isometric actions of the left m. quadriceps of seven subjects had been elicited by EMS (1-s train of 500-microseconds sine wave pulses at 50 Hz) or by VOL means. For both conditions, five sets of 10 muscle actions were executed at each of the three force levels equal to 25, 50, and 75% of maximal VOL isometric torque. There were 1-s, 1.5-min, and 30-min rests between muscle actions, sets, and torque levels, respectively. Transaxial proton MR images (TR/TE = 2,000/30, 60) of m. quadriceps femoris were obtained with a 1.5-T imager at rest and after completion of the five sets of isometric actions at each force level. MR image contrast shift, as indicated by T2 values > 1 SD above the mean resting muscle T2, was calculated per pixel. Torque declined approximately 18% (P < 0.05) during each EMS set independent of the preset relative force level but recovered between sets. EMS increased T2 values above rest (29 +/- 0.2 to 36 +/- 0.5, P < 0.05) in regions of muscle dispersed throughout a given cross section. The pattern of muscle stimulation, as reflected by increased T2 values, varied markedly among subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Feb 1993
    URL http://www.ncbi.nlm.nih.gov/pubmed/8458767

    Tags:

    • Adult
    • Electric Stimulation
    • Female
    • Humans
    • Isometric Contraction
    • Magnetic Resonance Imaging
    • Male
    • Muscle Contraction
    • Muscles
    • Thigh

    Attachments

    • Mapping of electrical muscle stimulation using MRI.pdf
    • PubMed Snapshot
  • Mechanisms underlying the training effects associated with neuromuscular electrical stimulation

    Author MH Trimble
    Author RM Enoka
    Abstract Although neuromuscular electrical stimulation (NMES) can increase the ability of muscle to exert force, the means by which this is accomplished seem to be different from those associated with voluntary exercise. The aim of the study was to determine whether the recruitment order of motor units elicited by over-the-muscle electrical stimulation is different from that achieved with voluntary activation of muscle. This difference was tested by comparing muscle twitch responses that were elicited by Hoffmann reflexes (H-reflexes) and direct motor responses (M-responses) and by examining the effect of submotor NMES on the twitch force associated with H-reflexes. Because H-reflexes represent the summed activity of many motor units, in a manner that is consistent with volitional activation, variation in the time to peak twitch force indicates changes in the population of motor units that contribute to the response. The results demonstrated that the percutaneous application of submotor NMES to the limbs of human subjects causes a faster-contracting population of motor units to be activated during a test H-reflex. Consequently, it seems that the application of NMES preferentially activates faster-contracting motor units, perhaps those that are normally only active at high exercise intensities under voluntary conditions.
    Publication PHYS THER
    Date April 1, 1991
    URL http://www.ptjournal.org/cgi/content/abstract/71/4/273

    Attachments

    • HighWire Snapshot
    • Mechanisms underlying the training effects associated with neuromuscular electrical stimulation.pdf
  • New look at force-frequency relationship of human skeletal muscle: effects of fatigue

    Author S A Binder-Macleod
    Author S C Lee
    Author A D Fritz
    Author L J Kucharski
    Abstract A muscle does not have a unique force-frequency relationship; rather, it is dynamic and depends on the activation history of muscle. The purpose of this study was to investigate the force-frequency relationship of nonfatigued and fatigued skeletal muscle with the use of both catchlike-inducing trains (CITs) that exploited the catchlike property of skeletal muscle and constant-frequency trains (CFTs). Quadriceps femoris muscles were studied during isometric contractions in twelve healthy subjects (5 females, 7 males). Both the peak force and force-time integrals produced in response to each stimulation train were analyzed. Compared with nonfatigued muscles, higher frequencies of activation were needed to produce comparable normalized peak forces when the muscles were fatigued (i.e., a "rightward" shift in the force-frequency relationship) for both the CFTs and the CITs. When using the normalized force-time integral to measure muscle performance, the CFTs required slightly higher frequencies to produce comparable normalized forces from fatigued muscles, but the CITs did not. Furthermore, when the muscles were fatigued, the CITs produced greater peak forces and force-time integrals than all comparable CFTs with frequencies </=20 pps. In general, the lower the frequency the greater the augmentation produced by the CITs. In addition, the CIT that elicited the greatest force-time integral produced a 25% greater force-time integral than the best CFT. Because the CITs augmented forces across a wide range of physiological relevant activation rates, these results may have important clinical implications when using electrical stimulation to aid patients with paralysis. The results of this study contribute to our understanding of the relationship between the activation pattern of a muscle and the force output produced.
    Publication Journal of Neurophysiology
    Date Apr 1998
    URL http://www.ncbi.nlm.nih.gov/pubmed/9535953

    Tags:

    • Adult
    • Analysis of Variance
    • Female
    • Humans
    • Isometric Contraction
    • Male
    • Muscle Fatigue
    • Muscle, Skeletal

    Attachments

    • New Look at Force-Frequency Relationship of Human Skeletal Muscle Effects of Fatigue.pdf
    • PubMed Snapshot
  • Recruitment Patterns in Human Skeletal Muscle During Electrical Stimulation

    Author Chris M Gregory
    Author C Scott Bickel
    Abstract Electromyostimulation (EMS) incorporates the use of electrical current to activate skeletal muscle and facilitate contraction. It is commonly used in clinical settings to mimic voluntary contractions and enhance the rehabilitation of human skeletal muscles. Although the beneficial effects of EMS are widely accepted, discrepancies concerning the specific responses to EMS versus voluntary actions exist. The unique effects of EMS have been attributed to several mechanisms, most notably a reversal of the recruitment pattern typically associated with voluntary muscle activation. This perspective outlines the authors&apos; contention that electrical stimulation recruits motor units in a nonselective, spatially fixed, and temporally synchronous pattern. Furthermore, it synthesizes the evidence that supports the contention that this recruitment pattern contributes to increased muscle fatigue when compared with voluntary actions. The authors believe the majority of evidence suggests that EMS-induced motor unit recruitment is nonselective and that muscle fibers are recruited without obvious sequencing related to fiber types.
    Publication PHYS THER
    Date April 1, 2005
    URL http://www.ptjournal.org/cgi/content/abstract/85/4/358

    Attachments

    • Gregory et Bickel - Recruitment patterns in human skeletal muscle - Phys Ther 2005.pdf
    • HighWire Snapshot
  • Russian electrical stimulation: the early experiments. (Perspective). - Free Online Library

    Author N Shkuratova
    Abstract Electrical stimulation is used extensively in physical therapy, and "Russian currents" have been advocated for use in increasing muscle force. (1,2) This form of electrical stimulation seems to us to be the least understood in terms of physiological effects. Russian currents are alternating currents (AC) at a frequency of 2.5 kHz that are burst modulated at a frequency of 50 Hz with a 50% duty cycle. The stimulus is applied for a 10-second "on" period followed by a 50-second "off" or rest period, with a recommended treatment time of 10 minutes per stimulation session. (1) This stimulation regimen regimen (called the "10/50/10" regimen), applied once daily over a period of weeks, has been claimed to result in force gains, but many of the claims appear to be anecdotal.
    Publication American Physical Therapy Association
    Date 2002
    URL http://www.thefreelibrary.com/Russian+electrical+stimulation:+the+early+experiments.+(Perspective).-a093081458

    Attachments

    • Protocol Russian current.pdf
    • Russian electrical stimulation: the early experiments. (Perspective). - Free Online Library
  • Skeletal muscle plasticity: cellular and molecular responses to altered physical activity paradigms

    Author Kenneth M Baldwin
    Author Fadia Haddad
    Abstract The goal of this article is to examine our current understanding of the chain of events known to be involved in the adaptive process whereby specific genes and their protein products undergo altered expression; specifically, skeletal muscle adaptation in response to altered loading states will be discussed, with a special focus on the regulation of the contractile protein, myosin heavy chain gene expression. This protein, which is both an important structural and regulatory protein comprising the contractile apparatus, can be expressed as different isoforms, thereby having an impact on the functional diversity of the muscle. Because the regulation of the myosin gene family is under the control of a complex set of processes including, but not limited to, activity, hormonal, and metabolic factors, this protein will serve as a cellular "marker" for studies of muscle plasticity in response to various mechanical perturbations in which the quantity and type of myosin isoform, along with other important cellular proteins, are altered in expression.
    Publication American Journal of Physical Medicine & Rehabilitation / Association of Academic Physiatrists
    Date Nov 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/12409810

    Tags:

    • Adaptation, Physiological
    • Animals
    • Electric Stimulation
    • Gene Expression Regulation
    • Humans
    • Hypertrophy
    • Insulin-Like Growth Factor I
    • Motor Activity
    • Muscle Contraction
    • Muscle, Skeletal
    • Muscular Atrophy
    • Myosin Heavy Chains
    • Protein Biosynthesis
    • Stress, Mechanical
    • Transcription, Genetic

    Attachments

    • Baldwin Skeletal Muscle Plasticity.pdf
    • PubMed Snapshot
  • Spatial fiber type distribution in normal human muscle : : Histochemical and tensiomyographical evaluation

    Author Raja Dahmane
    Author Srdjan Djordjevi&#x10d;
    Author Bostjan &#x160;imuni&#x10d;
    Author Vojko Valen&#x10d;i&#x10d;
    Abstract The variability of fiber type distribution in nine limb muscles was examined with histochemical and tensiomyographical (TMG) methods in two groups of 15 men aged between 17 and 40 years. The aim of this study was to determine the extent to which the relative occurrence of different fiber types and subtypes varies within human limb muscles in function to depth and to predict fiber type proportions with a non-invasive TMG method. The distribution of different fiber types varied within the muscles, as a function of depth, with a predominance of type 2b fibers at the surface and type 1 fibers in deeper regions of the muscle. For all the analyzed muscles the contraction times measured at stimulus intensity 10% of supramaximal stimulus (10% MS) were significantly (p<0.05) shorter than the contraction times measured at 50% of supramaximal stimulus intensity (50% MS). The Pearson&apos;s correlation coefficient between percentage of type 1 muscle fibers measured at the surface of the muscle and contraction time at 10% MS, obtained by TMG was statistically significant (r=0.76,P<0.01). Also the Pearson&apos;s correlation coefficient between percentage of type 1 muscle fibers measured in the deep region of the muscle and contraction time at 50% MS obtained by TMG was also statistically significant (r=0.90,P<0.001). These findings suggest that the contraction time obtained by TMG may be useful for non-invasive examining of muscle fiber types spatial distribution in humans. Keywords: Human limb skeletal muscle; Muscle fiber types distribution; Histochemistry; Tensiomyography
    Publication Journal of Biomechanics
    Date December 2005
    URL http://www.sciencedirect.com/science?
    _ob=ArticleURL&…

    Tags:

    • Histochemistry
    • Human limb skeletal muscle
    • Muscle fiber types distribution
    • Tensiomyography

    Attachments

    • ScienceDirect Snapshot
    • Spatial fiber type distribution in normal human muscle Histochemical and tensiomyographical evaluation.pdf
  • The acute effect of whole-body vibration on the hoffmann reflex

    Author W Jeffrey Armstrong
    Author Holly N Nestle
    Author David C Grinnell
    Author Lindsey D Cole
    Author Erica L Van Gilder
    Author Gabriel S Warren
    Author Elizabeth A Capizzi
    Abstract The extent to which motoneuron pool excitability, as measured by the Hoffmann reflex (H-reflex), is affected by an acute bout of whole-body vibration (WBV) was recorded in 19 college-aged subjects (8 male and 11 female; mean age 19 +/- 1 years) after tibial nerve stimulation. H/M recruitment curves were mapped for the soleus muscle by increasing stimulus intensity in 0.2- to 1.0-volt increments with 10-second rest intervals between stimuli, until the maximal M-wave and H-reflex were obtained. After determination of Hmax and Mmax, the intensity necessary to generate an H-reflex approximately 30% of Mmax (mean 31.5% +/- 4.1%) was determined and used for all subsequent measurements. Fatigue was then induced by 1 minute of WBV at 40 Hz and low amplitude (2-4 mm). Successive measurements of the H-reflex were recorded at the test intensity every 30 seconds for 30 minutes post fatigue. All subjects displayed a significant suppression of the H-reflex during the first minute post-WBV; however, four distinct recovery patterns were observed among the participants (alpha = 0.50). There were no significant differences between genders across time (P = 0.401). The differences observed in this study cannot be explained by level or type training. One plausible interpretation of these data is that the multiple patterns of recovery may display variation of muscle fiber content among subjects. Future investigation should consider factors such as training specificity and muscle fiber type that might contribute to the differing H-reflex response, and the effect of WBV on specific performance measures should be interpreted with the understanding that there may be considerable variability among individuals. Recovery times and sample size should be adjusted accordingly.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Mar 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/18550962

    Tags:

    • Adolescent
    • Adult
    • Electric Stimulation
    • Electromyography
    • H-Reflex
    • Humans
    • Male
    • Muscle Contraction
    • Muscle, Skeletal
    • Recovery of Function
    • Tibial Nerve
    • Vibration

    Attachments

    • PubMed Snapshot
    • The Acute Effect of Whole-Body Vibration on the Hoffmann Reflex.pdf
  • The effect of stimulus parameters on the recruitment characteristics of direct nerve stimulation

    Author P H Gorman
    Author J T Mortimer
    Abstract The effect of stimulus parameters on the recruitment characteristics of motor nerve was studied for regulated current monophasic and balanced charge biphasic stimuli. Results of a nerve model investigation indicated that the threshold difference between different diameter nerve fibers would be dependent on pulse width, the choice between monophasic and biphasic stimuli, and the delay between the primary cathodic and secondary anodic pulses. Threshold difference increased with decreasing pulse width, the greatest effects evident for pulses less than 100 microsec. Biphasic stimulation with no delay between pulses provided greater threshold separation than monophasic stimulation or biphasic stimulation with delay. Animal experiments, in which recruitment in a nerve trunk composed of mixed diameter nerve fibers was examined, showed a decrease in recruitment slope with a decrease in pulse width and with the use of a biphasic, zero delay pulse. These results were examined through muscle force measurements using both a metal loop electrode encircling the nerve trunk and a nerve cuff electrode, i. e., a loop electrode in an insulating tube.
    Publication IEEE Transactions on Bio-Medical Engineering
    Date Jul 1983
    URL http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?
    arnumber=4121663

    Tags:

    • Animals
    • Cats
    • Electric Stimulation
    • Electric Stimulation Therapy
    • Muscles
    • Nerve Fibers
    • Neural Conduction
    • Paralysis
    • Recruitment, Neurophysiological

    Attachments

    • PubMed Snapshot
  • The Effects Of Neuromuscular Electrical Stimulation Training On Abdominal Strength, Endurance, And Selected Anthropometric Measures

    Author John Porcari
    Author Jennifer Miller
    Author Kelly Cornwell
    Author Carl Foster
    Author Mark Gibson
    Author Karen McLean
    Author Tom Kernozek
    Abstract We studied the effects of self-administered neuromuscular electrical stimulation (NMES) on changes in strength, endurance, selected anthropometric measures, and subject&apos;s perceived shape and satisfaction of the abdominal wall. Twenty-four adults (experimental group) stimulated their abdominals 5 days per week (20-40 minutes per session) for 8 weeks and refrained from engaging in any additional exercise during the study. A control group (N=16) refrained from exercising the abdominals or engaging in any other exercise training during the study. Subjects were tested at the beginning, mid-point, and end of the study. Isometric strength of the abdominal muscles was tested using a isokinetic dynamometer, endurance was measured using the ACSM curl-up test, abdominal circumference was measured using a steel tape measure, and body shape and satisfaction were assessed via questionnaire. The stimulation group had a 58% increase in abdominal strength, whereas the control group did not change. The stimulation group also had a 100% increase in abdominal endurance versus a 28% increase in the control group. Waist circumference decreased by of 3.5 cm in the stimulation group compared to no significant change in the control group. All 24 subjects in the stimulation group felt that their midsections were more "toned" and "firmed" and 13/24 (54%) felt that their posture had improved as a result of the stimulation. None of the control group subjects reported changes in these parameters. There were no significant differences in body weight, BMI, or skinfold thickness over the course of the study in either group. NMES, as used in the current study, resulted in significant improvements in the muscular strength and endurance of the abdominal region, as well as subject&apos;s perceived shape and satisfaction of the mid-section.
    Publication Journal of Sports Science and Medicine
    Series 01 March 2005
    URL http://www.jssm.org/vol4/n1/9/v4n1-9text.php

    Attachments

    • JSSM- 2005, Vol.4, Issue 1, 66 - 75
    • v4n1-9pdf.pdf
  • Two theories of muscle strength augmentation using percutaneous electrical stimulation

    Author A Delitto
    Author L Snyder-Mackler
    Abstract Electrical stimulation of muscle is a commonly used, well-substantiated strategy that physical therapists use to augment strength in patients with muscle weakness. Two distinctly different theories of strength augmentation using percutaneous muscle stimulation are presented. The first theory proposes that augmentation of muscle strength with electrically elicited muscle contractions occurs in a similar manner to augmentation of muscle strength with voluntary exercise. Electrically elicited muscle contractions of relatively high intensity with low numbers of repetitions strengthen muscle proportionally to the external load on the muscle in a manner that is equivalent to voluntary contraction. The second theory proposes that augmentation of muscle strength using percutaneous stimulation is fundamentally different from augmentation of strength with voluntary exercise. This theory uses the physiological differences between electrically elicited and voluntary contractions, such as the reversal of motor unit recruitment order, as a basis for argument. Both theories are partially substantiated using published literature. Strategies for testing both theories are also presented.
    Publication Physical Therapy
    Date Mar 1990
    URL http://www.ncbi.nlm.nih.gov/pubmed/2406766

    Tags:

    • Electric Stimulation Therapy
    • Exercise
    • Humans
    • Muscle Contraction
    • Muscle Hypotonia
    • Neuromuscular Diseases

    Attachments

    • PubMed Snapshot
    • Two Theories of Muscle Strength Augmentation Usiing Percutaneous Electrical Stimulation.pdf
  • What does chronic electrical stimulation teach us about muscle plasticity?

    Author D Pette
    Author G Vrbová
    Abstract The model of chronic low-frequency stimulation for the study of muscle plasticity was developed over 30 years ago. This protocol leads to a transformation of fast, fatigable muscles toward slower, fatigue-resistant ones. It involves qualitative and quantitative changes of all elements of the muscle fiber studied so far. The multitude of stimulation-induced changes makes it possible to establish the full adaptive potential of skeletal muscle. Both functional and structural alterations are caused by orchestrated exchanges of fast protein isoforms with their slow counterparts, as well as by altered levels of expression. This remodeling of the muscle fiber encompasses the major, myofibrillar proteins, membrane-bound and soluble proteins involved in Ca2+ dynamics, and mitochondrial and cytosolic enzymes of energy metabolism. Most transitions occur in a coordinated, time-dependent manner and result from altered gene expression, including transcriptional and posttranscriptional processes. This review summarizes the advantages of chronic low-frequency stimulation for studying activity-induced changes in phenotype, and its potential for investigating regulatory mechanisms of gene expression. The potential clinical relevance or utility of the technique is also considered.
    Publication Muscle & Nerve
    Date Jun 1999
    URL http://www.ncbi.nlm.nih.gov/pubmed/10366220

    Tags:

    • Animals
    • Electric Stimulation
    • Gene Expression Regulation
    • Humans
    • Motor Neurons
    • Muscle Contraction
    • Muscle Fibers, Skeletal
    • Muscle, Skeletal
    • Phenotype
    • Time Factors

    Attachments

    • PubMed Snapshot


Back to Top

EMS in Sport

  • Activation of human plantar flexor muscles increases after electromyostimulation training

    Author Nicola A Maffiuletti
    Author Manuela Pensini
    Author Alain Martin
    Abstract Neuromuscular adaptations of the plantar flexor muscles were assessed before and subsequent to short-term electromyostimulation (EMS) training. Eight subjects underwent 16 sessions of isometric EMS training over 4 wk. Surface electromyographic (EMG) activity and torque obtained under maximal voluntary and electrically evoked contractions were analyzed to distinguish neural adaptations from contractile changes. After training, plantar flexor voluntary torque significantly increased under isometric conditions at the training angle (+8.1%, P < 0.05) and at the two eccentric velocities considered (+10.8 and +13.1%, P < 0.05). Torque gains were accompanied by higher normalized soleus EMG activity and, in the case of eccentric contractions, also by higher gastrocnemii EMG (P < 0.05). There was an 11.9% significant increase in both plantar flexor maximal voluntary activation (P < 0.01) and postactivation potentiation (P < 0.05), whereas contractile properties did not change after training. In the absence of a change in the control group, it was concluded that an increase in neural activation likely mediates the voluntary torque gains observed after short-term EMS training.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Apr 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/11896001

    Tags:

    • Adult
    • Electric Stimulation
    • Electromyography
    • Exercise
    • Humans
    • Isometric Contraction
    • Male
    • Muscle, Skeletal
    • Torque
    • Volition

    Attachments

    • Maffiuletti-Jap2002.pdf
    • PubMed Snapshot
  • Alteration of neuromuscular function after a prolonged road cycling race

    Author G Y Millet
    Author G P Millet
    Author G Lattier
    Author N A Maffiuletti
    Author R Candau
    Abstract The aim of this study was to characterize neuromuscular fatigue in knee extensor muscles after a prolonged cycling exercise. During the two days preceding a 140-km race (mean +/- SD duration: 278.2 +/- 24.9 min) and 15 to 30 min after, maximal percutaneous electrical stimulations were applied to the femoral nerve of 11 trained cyclists. Electrically evoked superimposed twitches and trains of 6 stimulations were delivered during isometric maximal voluntary contraction (MVC) to determine maximal voluntary activation (% VA). Knee extensors MVC decreased with fatigue from 158.2 +/- 29.6 to 144.2 +/- 30.0 Nm (p < 0.01), but no central activation failure was detected after the race. The average rate of twitch force development increased significantly from 414 +/- 106 to 466 +/- 102 N x m x s-1 (p < 0.05) and a tendency toward higher peak twitch tension (p = 0.052) was found in the fatigued state. Short tetanus at 20 Hz and 80 Hz were also applied to 4 cyclists, but these fused and unfused tetanic forces were not significantly modified with fatigue. From these results, it can be concluded that the small but significant isometric strength loss measured less than 30 min after the end of a long distance road cycling race is not due to central fatigue. It is also suggested that a raise in peak twitch tension is not necessarily associated with enhanced neuromuscular function.
    Publication International Journal of Sports Medicine
    Date Apr 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/12740737

    Tags:

    • Adult
    • Bicycling
    • Electric Stimulation
    • Humans
    • Knee
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Neuromuscular Junction
    • Physical Endurance

    Attachments

    • Maffiuletti 2009 Alteration of neuromuscular function after a prolonged road cycling race.pdf
    • PubMed Snapshot
  • Alterations of neuromuscular function after an ultramarathon

    Author G Y Millet
    Author R Lepers
    Author N A Maffiuletti
    Author N Babault
    Author V Martin
    Author G Lattier
    Abstract Neuromuscular fatigue of the knee extensor (KE) and plantar flexor (PF) muscles was characterized after a 65-km ultramarathon race in nine well-trained runners by stimulating the femoral and tibial nerves, respectively. One week before and immediately after the ultramarathon, maximal twitches were elicited from the relaxed KE and PF. Electrically evoked superimposed twitches of the KE were also elicited during maximal voluntary contractions (MVCs) to determine maximal voluntary activation. MVC and maximal voluntary activation decreased significantly after the ultramarathon (-30.2 +/- 18.0% and -27.7 +/- 13.0%, respectively; P < 0.001). Surprisingly, peak twitch increased after the ultramarathon from 15.8 +/- 6.3 to 19.7 +/- 3.3 N. m for PF (P < 0.01) and from 131.9 +/- 21.2 to 157.1 +/- 35.9 N for KE (P < 0.05). Also, shorter contraction and half-relaxation times were observed for both muscles. The compound muscle action potentials (M wave) were not significantly altered by the ultramarathon with the exception of the soleus, which showed a slightly higher M-wave amplitude after the running. From these results, it can be concluded that 65 km of running 1) severely depressed the maximal voluntary force capacity mainly because of a decrease in maximal voluntary activation, 2) potentiated the twitch mechanical response, and 3) did not change significantly the M-wave characteristics.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Feb 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/11796655

    Tags:

    • Adult
    • Electromyography
    • Electrophysiology
    • Humans
    • Male
    • Muscle Contraction
    • Muscle, Skeletal
    • Neuromuscular Junction
    • Physical Endurance
    • Running

    Attachments

    • PubMed Snapshot
  • Applications of Surface Electromyography In Strength and Conditioning

    Author Travis Beck
    Publication NSCA Paper

    Attachments

    • EMG.pdf
  • Central and peripheral fatigue after electrostimulation-induced resistance exercise

    Author Delphine Boerio
    Author Marc Jubeau
    Author Raphael Zory
    Author Nicola A Maffiuletti
    Abstract PURPOSE: To investigate central and peripheral fatigue induced by a typical session of electromyostimulation (EMS) of the triceps surae muscle. METHODS: A series of neuromuscular tests including voluntary and electrically evoked contractions were performed before and immediately after 13 min of EMS (75 Hz) in 10 healthy individuals. RESULTS: Maximal voluntary contraction torque of the plantar flexor muscles significantly decreased (-9.4%; P < 0.001) after EMS, and this was accompanied by an impairment of central activation, as attested by twitch interpolation results (P < 0.05), whereas soleus maximal Hoffmann reflex and tibialis anterior coactivation did not change significantly. Contractile properties associated with paired stimuli and maximal M-wave amplitude for both soleus and medial gastrocnemius muscles (-9.4 and -38.7%, respectively) were significantly affected by EMS (P < 0.05), whereas postactivation potentiation did not change. CONCLUSION: A single bout of EMS resulted in fatigue attributable to both central and peripheral factors. The most obvious alteration in the function of the central nervous system is a decrease in the quantity of the neural drive to muscle from the supraspinal centers. On the other hand, neuromuscular propagation failure was more evident for the muscle with the higher percentage of Type II fibers.
    Publication Medicine and Science in Sports and Exercise
    Date Jun 2005
    URL http://www.ncbi.nlm.nih.gov/pubmed/15947722

    Tags:

    • Adult
    • Arm
    • Electric Stimulation
    • Electromyography
    • H-Reflex
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Torque

    Attachments

    • Boerio-Msse2005.pdf
    • PubMed Snapshot
  • Central and peripheral fatigue of the knee extensor muscles induced by electromyostimulation

    Author R Zory
    Author D Boërio
    Author M Jubeau
    Author N A Maffiuletti
    Abstract The main purpose of this study was to characterise neuromuscular fatigue induced by 30 contractions of the knee extensor muscles evoked by electromyostimulation (EMS). Twelve healthy subjects were tested before and after a typical EMS session (frequency: 75 Hz, on-off ratio: 6.25 s on-20 s off) used for quadriceps femoris muscle strengthening. Surface electromyographic (EMG) activity and torque obtained during maximal voluntary and electrically evoked contractions were analysed to distinguish peripheral from central fatigue. Maximal voluntary torque of the knee extensor muscles decreased approximately 20 % (p < 0.001) following EMS. In the same way, peak torque associated to single (p < 0.05) and paired (p < 0.001) stimuli as well as M-wave amplitude (p < 0.05) significantly decreased as a result of EMS. The raw EMG activity of both vastus lateralis and rectus femoris muscle recorded during maximal voluntary isometric contraction significantly decreased after the session (-17.3 and -14.5 %, respectively) whereas no changes were observed when EMG signals were normalised to respective M-wave amplitudes. Similarly, voluntary activation estimated by using the twitch interpolation technique was unchanged following EMS. In conclusion, a typical session of EMS of the knee extensor muscles mainly induced neuromuscular propagation failure while excitation-contraction coupling and neural mechanisms were not significantly affected. It is recommended to interpret surface EMG data together with the corresponding M wave, at least for the knee extensor muscles, in order to distinguish peripheral from central causes of fatigue.
    Publication International Journal of Sports Medicine
    Date Dec 2005
    URL http://www.ncbi.nlm.nih.gov/pubmed/16320169

    Tags:

    • Adult
    • Electric Stimulation
    • Electromyography
    • Femoral Nerve
    • Humans
    • Isometric Contraction
    • Knee
    • Male
    • Muscle Fatigue
    • Muscle Relaxation
    • Muscle, Skeletal
    • Torque

    Attachments

    • PubMed Snapshot
    • Zory-Ijsm2005.pdf
  • Changes in the force-frequency relationship of the human quadriceps femoris muscle following electrically and voluntarily induced fatigue

    Author S A Binder-Macleod
    Author L R McDermond
    Abstract The purpose of this study was to identify the changes in the force-frequency relationship (FFR) of the human quadriceps femoris muscle following electrically and voluntarily induced fatigue. Twenty nondisabled subjects each participated in one experimental session to test the effects of electrically induced fatigue on the FFR; 10 of these subjects participated in a second session in which voluntarily induced fatigue was produced. Fatigue was induced by having subjects perform repeated, 8-second, isometric contractions followed by 12-second rests until 50% of the initial force was produced. Markedly decreased forces were seen at all frequencies tested following fatigue. Low frequency fatigue was observed following both fatiguing protocols. The frequencies needed to produce near-maximum forces did not shift with fatigue. These results suggest that the most appropriate stimulation frequency to use when activating skeletal muscle depends on both the percentage of tetanic force desired and the fatigue state of the muscle. This study also provides the clinician with data on the FFR of healthy human quadriceps femoris muscle prior to fatigue. [Binder-Macleod SA, McDermond LR. Changes in the force-frequency relationship of the human quadriceps femoris muscle following electrically and voluntarily induced fatigue.
    Publication Physical Therapy
    Date Feb 1992
    URL http://www.ncbi.nlm.nih.gov/pubmed/1549641

    Tags:

    • Adult
    • Electric Stimulation
    • Female
    • Humans
    • Isometric Contraction
    • Male
    • Muscles
    • Reference Values
    • Reproducibility of Results

    Attachments

    • PubMed Snapshot
  • Comparison between voluntary and stimulated contractions of the quadriceps femoris for growth hormone response and muscle damage

    Author Marc Jubeau
    Author Alessandro Sartorio
    Author Pier Giulio Marinone
    Author Fiorenza Agosti
    Author Jacques Van Hoecke
    Author Kazunori Nosaka
    Author Nicola A Maffiuletti
    Abstract This study aimed to compare voluntary and stimulated exercise for changes in muscle strength, growth hormone (GH), blood lactate, and markers of muscle damage. Nine healthy men had two leg press exercise bouts separated by 2 wk. In the first bout, the quadriceps muscles were stimulated by biphasic rectangular pulses (75 Hz, duration 400 mus, on-off ratio 6.25-20 s) with current amplitude being consistently increased throughout 40 contractions at maximal tolerable level. In the second bout, 40 voluntary isometric contractions were performed at the same leg press force output as the first bout. Maximal voluntary isometric strength was measured before and after the bouts, and serum GH and blood lactate concentrations were measured before, during, and after exercise. Serum creatine kinase (CK) activity and muscle soreness were assessed before, immediately after, and 24, 48, and 72 h after exercise. Maximal voluntary strength decreased significantly (P < 0.05) after both bouts, but the magnitude of the decrease was significantly (P < 0.05) greater for the stimulated contractions (-22%) compared with the voluntary contractions (-9%). Increases in serum GH and lactate concentrations were significantly (P < 0.05) larger after the stimulation compared with the voluntary exercise. Increases in serum CK activity and muscle soreness were also significantly (P < 0.05) greater for the stimulation than voluntary exercise. It was concluded that a single bout of electrical stimulation exercise resulted in greater GH response and muscle damage than voluntary exercise.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Jan 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/17975128

    Tags:

    • Adult
    • Creatine Kinase, MM Form
    • Electric Stimulation
    • Exercise
    • Human Growth Hormone
    • Humans
    • Isometric Contraction
    • Lactic Acid
    • Male
    • Muscle Strength
    • Muscular Diseases
    • Pain
    • Pain Measurement
    • Quadriceps Muscle
    • Time Factors

    Attachments

    • Jubeau jap2008.pdf
    • PubMed Snapshot
  • Differences in Electrical Stimulation Thresholds between Men and Women

    Author Nicola A Maffiuletti
    Author Azael J Herrero
    Author Marc Jubeau
    Author Franco M Impellizzeri
    Author Mario Bizzini
    Abstract OBJECTIVE: Surface electrical stimulation (ES) of skeletal muscle is used in a variety of clinical settings in healthy and unhealthy subjects of both sexes. Although women generally present larger amounts of subcutaneous adipose tissue than men, which could limit current flow to the stimulated muscle, sex-related differences in ES current levels have not been clearly demonstrated to date. We report data from healthy men and women. METHODS: Sensory (current perception), motor (minimal knee extension torque production), and supramotor thresholds (10% of the maximal voluntary knee extension torque) and perceived pain during surface ES of the quadriceps femoris muscle were investigated in 40 healthy volunteers (20 men, 20 women). RESULTS: Sensory threshold was lower in women than in men (-43%; p < 0.001). Similarly, female muscles required lower current amplitudes to attain the supramotor threshold (-17%; p < 0.01). The Visual Analogue Scale pain score was significantly greater in women than in men at motor threshold (+112%; p < 0.01) but not at supramotor threshold (+36%; p > 0.05). INTERPRETATION: Collectively, our data demonstrate higher sensory and supramotor excitability to surface ES in female subjects and provide further evidence for a neurophysiological explanation for more pronounced pain perception in women. These observations may help clinicians to better understand the sex-specific response to ES and to design more rational stimulation treatments with the ultimate goal of optimizing patient care and safety.
    Publication Annals of Neurology
    Date Apr 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/18300313

    Tags:

    • Adult
    • Electric Stimulation
    • Evoked Potentials, Motor
    • Female
    • Humans
    • Male
    • Muscle, Skeletal
    • Pain Measurement
    • Sensory Thresholds
    • Sex Characteristics

    Attachments

    • Differences in electrical stimulation thresholds between men and women.pdf
    • PubMed Snapshot
  • Effect of combined electrostimulation and plyometric training on vertical jump height

    Author Nicola A Maffiuletti
    Author Sergio Dugnani
    Author Matteo Folz
    Author Ermano Di Pierno
    Author Franco Mauro
    Abstract PURPOSE: This study investigated the influence of a 4-wk combined electromyostimulation (EMS) and plyometric training program on the vertical jump performance of 10 volleyball players. METHODS: Training sessions were carried out three times weekly. Each session consisted of three main parts: EMS of the knee extensor muscles (48 contractions), EMS of the plantar flexor muscles (30 contractions), and 50 plyometric jumps. Subjects were tested before (week 0), during (week 2), and after the training program (week 4), as well as once more after 2 wk of normal volleyball training (week 6). Different vertical jumps were carried out, as well as maximal voluntary contraction (MVC) of the knee extensor and plantar flexor muscles. RESULTS: At week 2, MVC significantly increased (+20% knee extensors, +13% plantar flexors) as compared to baseline ( < 0.05). After the 4-wk training program, different vertical jumps considered were also significantly higher compared to pretraining ( < 0.001), and relative gains were comprised between 8-10% (spike-counter movement jump) and 21% (squat jump). The significant increases in maximal strength and explosive strength produced by the present training program were subsequently maintained after an additional 2 wk of volleyball training. CONCLUSION: EMS combined with plyometric training has proven useful for the improvement of vertical jump ability in volleyball players. This combined training modality produced rapid increases (approximately 2 wk) of the knee extensors and plantar flexors maximal strength. These adaptations were then followed by an improvement in general and specific jumping ability, likely to affect performance on the court. In conclusion, when EMS resistance training is proposed for vertical jump development, specific work out (e.g., plyometric) must complement EMS sessions to obtain beneficial effects.
    Publication Medicine and Science in Sports and Exercise
    Date Oct 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/12370566

    Tags:

    • Adult
    • Electric Stimulation
    • Humans
    • Isometric Contraction
    • Knee
    • Male
    • Movement
    • Muscle, Skeletal
    • Sports
    • Time Factors

    Attachments

    • Maffiuletti-Msse2002.pdf
    • PubMed Snapshot
  • Effect of electromyostimulation training on soleus and gastrocnemii H- and T-reflex properties

    Author Nicola A Maffiuletti
    Author Manuela Pensini
    Author Gil Scaglioni
    Author Alessandra Ferri
    Author Yves Ballay
    Author Alain Martin
    Abstract When muscle is artificially activated, as with electromyostimulation (EMS), action potentials are evoked in both intramuscular nerve branches and cutaneous receptors, therefore activating spinal motoneurons reflexively. Maximal soleus and gastrocnemii H- and T-reflex and the respective mechanical output were thus quantified to examine possible neural adaptations induced at the spinal level by EMS resistance training. Eight subjects completed 16 sessions of isometric EMS (75 Hz) over a 4-week period. Maximal soleus and gastrocnemii M wave (M(max)), H reflex (H(max)) and T reflex (T(max)) were compared between before and after training, together with the corresponding plantar flexor peak twitch torque. No significant changes were observed for electromechanical properties of H(max) reflex following EMS. On the other hand, peak twitch torque produced by T(max), but not by equal-amplitude H reflex, significantly increased as a result of training (+21%, P<0.05). These changes were associated with a trend towards a significant increase for normalized gastrocnemii (+21%, P=0.07) but not soleus T(max) reflex. It is concluded that, contrary to results previously obtained after voluntary physical training, EMS training of the plantar flexor muscles did not affect alpha motoneuron excitability and/or presynaptic inhibition, as indicated by H-reflex results. On the other hand, in the absence of change in a control group, T(max) electromechanical findings indicated that: (1). equal-amplitude H- and T-reflex adapted differently to EMS resistance training; and (2). EMS had an effect on gastrocnemii but not on soleus muscle, perhaps because of the differences in respective motor unit characteristics (e.g., axon diameter).
    Publication European Journal of Applied Physiology
    Date Nov 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/12923640

    Tags:

    • Action Potentials
    • Adaptation, Physiological
    • Adult
    • Electric Stimulation Therapy
    • H-Reflex
    • Humans
    • Male
    • Motor Neurons
    • Muscle, Skeletal
    • Spinal Nerves
    • Torque

    Attachments

    • Maffiuletti-Ejap2003.pdf
    • PubMed Snapshot
  • Effects of electromyostimulation training and volleyball practice on jumping ability

    Author Davide Malatesta
    Author Fabio Cattaneo
    Author Sergio Dugnani
    Author Nicola A Maffiuletti
    Abstract The aim of this study was to investigate the influence of a 4-week electromyostimulation (EMS) training program on the vertical jump performance of 12 volleyball players. EMS sessions were incorporated into volleyball sessions 3 times weekly. EMS consisted of 20-22 concomitant stimulations of the knee extensor and plantar flexor muscles and lasted approximately 12 minutes. No significant changes were observed after EMS training for squat jump (SJ) and counter movement jump (CMJ) performance, while the mean height and the mean power maintained during 15 seconds of consecutive CMJs significantly increased by approximately 4% (p < 0.05). Ten days after the end of EMS training, the jumping height significantly (p < 0.05) increased compared with baseline also for single jumps (SJ +6.5%, CMJ +5.4%). When the aim of EMS resistance training is to enhance vertical jump ability, sport-specific workouts following EMS would enable the central nervous system to optimize the control to neuromuscular properties.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Aug 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/12930189

    Tags:

    • Adolescent
    • Analysis of Variance
    • Biomechanics
    • Electric Stimulation
    • Humans
    • Knee
    • Male
    • Movement
    • Muscle Contraction
    • Muscle, Skeletal
    • Physical Education and Training
    • Sports

    Attachments

    • Malatesta-Jscr2003.pdf
    • PubMed Snapshot
  • Effects of electromyostimulation training on muscle strength and power of elite rugby players

    Author Nicolas Babault
    Author Gilles Cometti
    Author Michel Bernardin
    Author Michel Pousson
    Author Jean-Claude Chatard
    Abstract The present study investigated the influence of a 12-week electromyostimulation (EMS) training program performed by elite rugby players. Twenty-five rugby players participated in the study, 15 in an electrostimulated group and the remaining 10 in a control group. EMS was conducted on the knee extensor, plantar flexor, and gluteus muscles. During the first 6 weeks, training sessions were carried out 3 times a week and during the last 6 weeks, once a week. Isokinetic torque of the knee extensors was determined at different eccentric and concentric angular velocities ranging from -120 to 360 degrees .s(-1). Scrummaging and full squat strength, vertical jump height and sprint-running times were also evaluated. After the first 6 weeks of EMS, only the squat strength was significantly improved (+8.3 +/- 6.5%; p < 0.01). After the 12th week, the -120 degrees .s(-1) maximal eccentric, 120 and 240 degrees .s(-1) maximal concentric torque (p < 0.05), squat strength (+15.0 +/- 8.0%; p < 0.001), squat jump (+10.0 +/- 9.5%; p < 0.01), and drop jump from a 40-cm height (+6.6 +/- 6.1%; p < 0.05) were significantly improved. No significant change was observed for the control group. A 12-week EMS training program demonstrated beneficial effects on muscle strength and power in elite rugby players on particular tests. However, rugby skills such as scrummaging and sprinting were not enhanced.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date May 2007
    URL http://www.ncbi.nlm.nih.gov/pubmed/17530954

    Tags:

    • Adaptation, Physiological
    • Adult
    • Analysis of Variance
    • Electric Stimulation
    • Football
    • Humans
    • Male
    • Muscle Strength
    • Muscle, Skeletal
    • Physical Education and Training
    • Task Performance and Analysis
    • Torque

    Attachments

    • effects_of_electrostimulation_traini.pdf
    • PubMed Snapshot
  • Effects of electromyostimulation versus voluntary isometric training on elbow flexor muscle strength

    Author Serge S Colson
    Author Alain Martin
    Author Jacques Van Hoecke
    Abstract The purpose of this study was to determine whether 7 weeks of standardized (same number and duration of repetitions, sets and rest strictly identical) electromyostimulation training of the elbow flexor muscles would induce strength gains equivalent to those of voluntary isometric training in isometric, eccentric and concentric contractions. Twenty-five males were randomly assigned to an electromyostimulated group (EMS, n=9), a voluntary isometric group (VOL, n=8), or a control group (CON, n=8). Maximal voluntary isometric, eccentric and concentric strength, electromyographic (EMG) activity of the biceps and triceps brachii muscles, elbow flexor muscle activation (twitch interpolation technique) and contractile properties were assessed before and after the training period. The main findings were that the isometric torque gains of EMS were greater than those of VOL after the training period (P<0.01) and that the eccentric and concentric torque gains were equivalent. In both groups, we observed that the mechanical twitch (Pt) was increased (P<0.05) and that torque improvements were not mediated by neural adaptations. Considering the respective intensities of the training programs (i.e., submaximal contractions for EMS versus maximal for VOL), it can be concluded that electromyostimulation training would be more efficient than voluntary isometric training to improve both isometric and dynamic strength.
    Publication Journal of Electromyography and Kinesiology: Official Journal of the International Society of Electrophysiological Kinesiology
    Date Oct 2009
    URL http://www.ncbi.nlm.nih.gov/pubmed/18621547

    Tags:

    • Elbow Joint
    • Electric Stimulation
    • Exercise
    • Humans
    • Isometric Contraction
    • Male
    • Muscle Strength
    • Muscle, Skeletal
    • Physical Fitness
    • Volition
    • Young Adult
  • Electrical muscle stimulation for deep stabilizing muscles in abdominal wall

    Author Simon Coghlan
    Author Louis Crowe
    Author Ulrik McCarthyPersson
    Author Conor Minogue
    Author Brian Caulfield
    Abstract Low back pain is associated with dysfunction in recruitment of muscles in the lumbopelvic region. Effective rehabilitation requires preferential activation of deep stabilizing muscle groups. This study was carried out in order to quantify the response of deep stabilizing muscles (transverses abdominis) and superficial muscle in the abdominal wall (external oblique) to electrical muscle stimulation (EMS). Results demonstrate that EMS can preferentially stimulate contractions in the deep stabilizers and may have significant potential as a therapeutic intervention in this area, pending further refinements to the technology.
    Publication Conference Proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference
    Date 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/19163276

    Tags:

    • Abdomen
    • Abdominal Muscles
    • Abdominal Wall
    • Adult
    • Algorithms
    • Electric Stimulation Therapy
    • Humans
    • Middle Aged
    • Muscle Contraction
    • Muscles
    • Ultrasonography
  • Electromyostimulation and plyometric training effects on jumping and sprint time

    Author J A Herrero
    Author M Izquierdo
    Author N A Maffiuletti
    Author J García-López
    Abstract This study compared the effects of four-week training periods of electromyostimulation (EMS), plyometric training (P), or combined EMS and P training of the knee extensor muscles on 20 m sprint time (ST), jumping ability (Squat jump [SJ] and Countermovement jump [CMJ]), maximal isometric strength (MVC), and muscle cross-sectional area (CSA). Forty subjects were randomly assigned to one of the four treatment groups: electromyostimulation (EG), plyometric (PG), combined EMG, and P (EPG), that took place 4 times per week, and a control group (CG). Subjects were tested before and after the training program, as well as once more after 2 wk of detraining. A significant improvement (p < 0.05) in ST was observed after training (2.4 %) in EG while a significant slowing (p < 0.05) was observed (- 2.3 %) in EPG. Significant increases in EPG (p < 0.05) were observed in SJ (7.5 %) and CMJ (7.3 %) after training, while no significant changes in both jumps were observed after training and detraining for EG. A significant increase (p < 0.05) in MVC was observed after training (9.1 %) and after detraining (8.1 %) in EG. A significant increase (p < 0.05) in MVC was observed after training (16.3 %) in EPG. A significant increase (p < 0.01) in CSA was observed after training in EG (9.0 %) and in EPG (7.1 %). EMS combined with plyometric training increased the jumping height and sprint run in physically active men. In addition, EMS alone or EMS combined with plyometric training leads to increase maximal strength and to some hypertrophy of trained muscles. However, EMS training alone did not result in any improvement in jumping explosive strength development or even interfered in sprint run.
    Publication International Journal of Sports Medicine
    Date Jul 2006
    URL http://www.ncbi.nlm.nih.gov/pubmed/16802248

    Tags:

    • Adult
    • Analysis of Variance
    • Electric Stimulation
    • Humans
    • Isometric Contraction
    • Knee
    • Male
    • Movement
    • Muscle, Skeletal
    • Physical Education and Training
    • Running
    • Sports
    • Time Factors

    Attachments

    • Herrero-Ijsm2006.pdf
    • PubMed Snapshot
  • Electrostimulation training effects on the physical performance of ice hockey players

    Author Franck Brocherie
    Author Nicolas Babault
    Author Gilles Cometti
    Author Nicola Maffiuletti
    Author Jean-Claude Chatard
    Abstract PURPOSE: The aim of this study was to examine the influence of a short-term electromyostimulation (EMS) training program on the strength of knee extensors, skating, and vertical jump performance of a group of ice hockey players. METHODS: Seventeen ice hockey players participated in this study, with nine in the electrostimulated group (ES) and the remaining height as controls (C). EMS sessions consisted of 30 contractions (4-s duration, 85 Hz) and were carried out 3x wk for 3 wk. Isokinetic strength of the knee extensor muscles was determined with a Biodex dynamometer at different eccentric and concentric angular velocities (angular velocities ranging from -120 to 300 degrees .s). Jumping ability was evaluated during squat jump (SJ), countermovement jump (CMJ), drop jump (DJ), and 15 consecutive CMJ (15J). Sprint times for 10- and 30-m skates in specific conditions were measured using an infrared photoelectric system. RESULTS: After 3 wk of EMS training, isokinetic torque increased significantly (P<0.05) for ES group in eccentric (-120 and -60 degrees .s) and concentric conditions (60 and 300 degrees .s), whereas vertical jump height decreased significantly (P<0.05) for SJ (-2.9+/-2.4 cm), CMJ (-2.1+/-2.0 cm), and DJ (-1.3+/-1.1 cm). The 10-m skating performance was significantly improved (from 2.18+/-0.20 to 2.07+/-0.09 s, before and after the 3-wk EMS period, respectively; P<0.05). CONCLUSION: It was demonstrated that an EMS program of the knee extensors significantly enhanced isokinetic strength (eccentric and for two concentric velocities) and short skating performance of a group of ice hockey players.
    Publication Medicine and Science in Sports and Exercise
    Date Mar 2005
    URL http://www.ncbi.nlm.nih.gov/pubmed/15741845

    Tags:

    • Adaptation, Physiological
    • Adult
    • Electric Stimulation
    • Hockey
    • Humans
    • Muscle, Skeletal
    • Physical Education and Training
    • Task Performance and Analysis
    • Torque

    Attachments

    • Electrostimulation Training Effects on the Physical Performance.pdf
    • PubMed Snapshot
  • Feasibility and efficacy of progressive electrostimulation strength training for competitive tennis players

    Author Nicola A Maffiuletti
    Author Jacopo Bramanti
    Author Marc Jubeau
    Author Mario Bizzini
    Author Gaëlle Deley
    Author Gilles Cometti
    Abstract The purpose of this preliminary study was to show the feasibility of electrostimulation (ES) strength exercise incorporated into tennis sessions during the preparatory season of competitive players, and its impact on anaerobic performance. Twelve tennis players (5 men, 7 women) completed 9 sessions of quadriceps ES (duration: 16 minutes; frequency: 85 Hz; on-off ratio: 5.25-25 seconds) during 3 weeks. The ES sessions were integrated into tennis training sessions. Subjects were baseline tested and retested 1 (week 4), 2 (week 5), 3 (week 6), and 4 weeks (week 7) after the ES training program for maximal quadriceps strength, vertical jump height, and shuttle sprint time. Participants were able to progressively increase ES current amplitude and evoked force throughout the 9 training sessions, with an optimal treatment compliance of 100%. Maximal quadriceps strength significantly increased during the entire duration of the experiment (p < 0.001). Countermovement jump height at week 5 (+5.3%) and week 6 (+6.4%) was significantly higher than at baseline (p < 0.05). In addition, 2 x 10-m sprint time at week 6 was significantly shorter (-3.3%; p = 0.004) compared with pretraining. The 3-week ES strength training program was successfully incorporated into preseason tennis training with a linear progression in all training parameters. Throughout the study period, a delayed enhancement of anaerobic power and stretch-shortening cycle performance was observed. Progressive ES strength training may be safely included in the early tennis season and can lead to improvements in the anaerobic performance of men and women players.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Mar 2009
    URL http://www.ncbi.nlm.nih.gov/pubmed/19209077

    Attachments

    • Feasibility and efficacy of progressive electrostimulation strength training for competitive tennis players.pdf
    • PubMed Snapshot
  • GH responses to two consecutive bouts of neuromuscular electrical stimulation in healthy adults

    Author A Sartorio
    Author M Jubeau
    Author F Agosti
    Author A De Col
    Author N Marazzi
    Author C L Lafortuna
    Author N A Maffiuletti
    Abstract BACKGROUND: It is well established that repeated GHRH administration or repeated voluntary exercise bouts are associated with a complete blunting of GH responsiveness when the administration of the second stimulus follows the first one after a 2-h interval. AIM: To evaluate GH responses to neuromuscular electrical stimulation (NMES) in healthy adults. METHODS: Six volunteers (mean age+/-s.d. 31.7+/-5.5 years) were studied before and after two consecutive bouts of NMES exercise (a series of 20 contractions at the maximum of individual tolerance, frequency: 75 Hz, pulse duration: 400 mus, on-off ratio: 6.25-20 s) administered at a 2-h interval. RESULTS: Baseline GH levels (mean: 0.3+/-0.2 ng/ml) significantly increased after the first NMES (peak: 4.2+/-3.7 ng/ml), with a complete normalization after 120 min (0.3+/-0.3 ng/ml). The administration of the second bout of NMES of comparable characteristics also resulted in a significant GH increase (peak: 5.2+/-3.2 ng/ml), which was comparable with that observed after the previous one. GH net incremental area under the curve after the first and second bouts of NMES were not significantly different (155.1+/-148.5 and 176.9+/-123.3 ng/ml per h, P=0.785). CONCLUSIONS: Unlike repeated pharmacological stimuli and voluntary exercise bouts, subsequent sessions of NMES administered at a 2-h interval appear to circumvent feedback mechanisms and to re-induce the GH responses, thus indicating a possible different underlying mechanism elicited by different GH-releasing stimuli.
    Publication European Journal of Endocrinology / European Federation of Endocrine Societies
    Date Mar 2008
    URL http://www.ncbi.nlm.nih.gov/pubmed/18299463

    Tags:

    • Adult
    • Electric Stimulation
    • Exercise
    • Feedback, Biochemical
    • Growth Hormone-Releasing Hormone
    • Human Growth Hormone
    • Humans
    • Hydrocortisone
    • Lactic Acid
    • Male
    • Muscle Strength
    • Quadriceps Muscle

    Attachments

    • PubMed Snapshot
    • Sartorio-Eje2008.pdf
  • Late neural adaptations to electrostimulation resistance training of the plantar flexor muscles

    Author Marc Jubeau
    Author Raphaël Zory
    Author Julien Gondin
    Author Alain Martin
    Author Nicola A Maffiuletti
    Abstract The present study aimed to examine early and late neural adaptations to short-term electrostimulation training of the plantar flexor muscles. Changes in triceps surae muscle activation (twitch interpolation), maximal electromyographic (EMG) activity, H-reflex amplitudes and antagonist coactivation were investigated after electrostimulation training (4 weeks) and after 4 weeks of detraining in a group of ten young healthy men. Maximal voluntary contraction torque was significantly higher (P < 0.01) after training (+19.4%) and detraining (+17.2%) with respect to baseline. Activation level, soleus and lateral gastrocnemius EMG normalized to the maximal M-wave significantly increased as a result of training (P < 0.05), and these gains were preserved after detraining, excepted for soleus EMG. Maximal H reflex to maximal M wave ratio increased significantly between baseline and detraining for both soleus and lateral gastrocnemius muscles (P < 0.05). Tibialis anterior coactivation was unchanged after training but significantly decreased after the detraining period (P < 0.01). Short-term electrostimulation resistance training was accompanied by early (increased muscle activation and EMG activity) and late neural adaptations (increased spinal reflex amplitude and decreased coactivation), likely explaining the increase and then the preservation of the maximal voluntary strength. These effects may help in conceiving and programming effective electrostimulation therapy programs for both healthy and immobilized plantar flexor muscles.
    Publication European Journal of Applied Physiology
    Date Sep 2006
    URL http://www.ncbi.nlm.nih.gov/pubmed/16944193

    Tags:

    • Adaptation, Physiological
    • Adult
    • Ankle Joint
    • Electric Stimulation
    • Exercise
    • Humans
    • Male
    • Muscle Contraction
    • Muscle, Skeletal
    • Neuronal Plasticity
    • Physical Exertion
    • Physical Fitness
    • Reflex, Abnormal

    Attachments

    • Jubeau-Ejap2006.pdf
    • PubMed Snapshot
  • Neuromuscular adaptations to electrostimulation resistance training

    Author Nicola A Maffiuletti
    Author Raphael Zory
    Author Danilo Miotti
    Author Maria A Pellegrino
    Author Marc Jubeau
    Author Roberto Bottinelli
    Abstract A combination of in vivo and in vitro analyses was performed to investigate muscular and neural adaptations of the weaker (nondominant) quadriceps femoris muscle of one healthy individual to short-term electrostimulation resistance training. The increase in maximal voluntary strength (+12%) was accompanied by neural (cross-education effect and increased muscle activation) and muscle adaptations (impairment of whole-muscle contractile properties). Significant changes in myosin heavy chain (MHC) isoforms relative content (+22% for MHC-2A and -28% for MHC-2X), single-fiber cross-sectional area (+27% for type 1 and +6% for type 2A muscle fibers), and specific tension of type 1 (+67%) but not type 2A fibers were also observed after training. Plastic changes in neural control confirm the possible involvement of both spinal and supraspinal structures to electrically evoked contractions. Changes at the single muscle fiber level induced by electrostimulation resistance training were significant and preferentially affected slow, type 1 fibers.
    Publication American Journal of Physical Medicine & Rehabilitation / Association of Academic Physiatrists
    Date Feb 2006
    URL http://www.ncbi.nlm.nih.gov/pubmed/16428910

    Tags:

    • Adaptation, Physiological
    • Adult
    • Biopsy, Needle
    • Electric Stimulation
    • Electromyography
    • Humans
    • Isometric Contraction
    • Male
    • Muscle Fibers, Fast-Twitch
    • Muscle Fibers, Slow-Twitch
    • Muscle, Skeletal
    • Myosin Heavy Chains
    • Physical Education and Training
    • Protein Isoforms
    • Torque

    Attachments

    • Maffiuletti-Ajpmr2006.pdf
    • PubMed Snapshot
  • Presentation: EMS in Sport

    Author Nicola A Maffiuletti
    Abstract EMS Myths and reality in Sport and normal subjects
    Date 2005

    Attachments

    • Aggiornamenti elettrostimolazione (1a PARTE).pdf
    • Aggiornamenti elettrostimolazione (2a PARTE).pdf
    • Aggiornamenti elettrostimolazione (3a PARTE).pdf
    • Aggiornamenti elettrostimolazione (4a PARTE).pdf
  • Random motor unit activation by electrostimulation

    Author M Jubeau
    Author J Gondin
    Author A Martin
    Author A Sartorio
    Author N A Maffiuletti
    Abstract Whether the involvement of motor units is different between surface neuromuscular electrostimulation and voluntary activation remains an unresolved issue. The aim of this pilot study was to verify if motor unit activation during electrostimulation is nonselective/random (i.e., without obvious sequencing related to fibre type), as recently suggested by Gregory and Bickel [6]. Sixteen healthy men randomly performed submaximal isometric contractions (10-s duration) of the quadriceps femoris muscle at 20, 40 and 60 % of maximal voluntary torque under both stimulated and voluntary conditions. During the contractions, paired stimuli were delivered to the femoral nerve (twitch interpolation technique) and the characteristics of the superimposed doublet were compared between the two conditions. For each torque level, time-to-peak torque was significantly longer (p range = 0.05 - 0.0002) during electrostimulation compared to voluntary contractions. Moreover, time-to-peak torque during voluntary trials decreased significantly when increasing the torque level from 20 to 60 % of maximal voluntary torque (p range = 0.03 - 0.0001), whereas it was unchanged during electrostimulation. In conclusion, over-the-muscle electrostimulation would neither result in motor unit recruitment according to Henneman&apos;s size principle nor would it result in a reversal in voluntary recruitment order. During electrostimulation, muscle fibres are activated without obvious sequencing related to fibre type.
    Publication International Journal of Sports Medicine
    Date Nov 2007
    URL http://www.ncbi.nlm.nih.gov/pubmed/17525881

    Tags:

    • Adult
    • Electric Stimulation
    • Humans
    • Isometric Contraction
    • Male
    • Muscle Contraction
    • Muscle Fibers, Skeletal
    • Muscle, Skeletal
    • Pilot Projects
    • Quadriceps Muscle
    • Recruitment, Neurophysiological
    • Torque

    Attachments

    • Jubeau-Ijsm2007.pdf
    • PubMed Snapshot
  • Science and Practice of Strength Training, Second Edition

    Author Vladimir M. Zatsiorsky
    Author William J. Kraemer
    Abstract This new second edition of Science and Practice of Strength Training comes with many additions and changes. A new coauthor, Dr. William Kraemer, joins Dr. Vladimir Zatsiorsky in expanding on the principles and concepts needed for training athletes. Among Dr. Kraemer’s contributions are three new chapters targeting specific populations—women, young athletes, and seniors—plus the integration of new concepts into the other chapters. Together the authors have trained more than 1,000 elite athletes, including Olympic, world, continental, and national champions and record holders. The concepts they divulge are influenced by both Eastern European and North American perspectives. The authors integrate those concepts in solid principles, practical insights, coaching experiences, and directions based on scientific findings. This edition is much more practical than its predecessor; to this end, the book provides the practitioner with the understanding to craft strength training programs based on individuals’ needs. Science and Practice of Strength Training, Second Edition, shows that there is no one program that works for any one person at all times or for all conditions. This book addresses the complexity of strength training programs while providing straightforward approaches to take under specific circumstances. Those approaches are applied to new physiological concepts and training practices, which provide readers with the most current information in the science and practice of strength training. The approaches are also applied to the three new chapters, which will help readers design safe and effective strength training programs for women, young athletes, and seniors. In addition, the authors provide examples of strength training programs to demonstrate the principles and concepts they explain in the book. The book is divided into three parts. Part I focuses on the basis of strength training, detailing concepts, task-specific strength, and athlete-specific strength. Part II covers methods of strength conditioning, delving into training intensity, timing, strength exercises, injury prevention, and goals. Part III explores training for specific populations. The book also includes suggested readings that can further aid readers in developing strength training programs. This expanded and updated coverage of strength training concepts will ground readers in the understanding they need in order to develop appropriate strength training programs for each person that they work with.
    Edition 2
    Publisher Human Kinetics Publishers
    Date 2006-05-30

    Attachments

    • Amazon.com Link
    • Science and Practice of Strength Training - EMS - Zatsiorsky 1995.pdf
  • The effects of electromyostimulation training and basketball practice on muscle strength and jumping ability

    Author N A Maffiuletti
    Author G Cometti
    Author I G Amiridis
    Author A Martin
    Author M Pousson
    Author J C Chatard
    Abstract The aim of this study was to investigate the influence of a 4-week electromyostimulation training program on the strength of the knee extensors and the vertical jump performance of 10 basketball players. Electromyostimulation sessions were carried out 3 times weekly; each session consisted of 48 contractions. Testing was carried out before and after the electromyostimulation training program (week 4) and once more after 4 weeks of normal basketball training (week 8). At week 4, isokinetic strength increased significantly (p < 0.05) at eccentric and high concentric velocities (between 180 and 360 x s(-1)); this was not the case for low concentric velocities (60 and 120 degrees x s(-1)). Electromyostimulation training increased also isometric strength at the two angles adjacent to the training angle (p < 0.01). Squat jump increased significantly by 14% at week 4 (p < 0.01), whereas counter movement-jump showed no change. At week 8, gains in isokinetic, isometric strength and squat-jump performance were maintained and the counter movement jump performance increased significantly by 17% (p<0.01). Electromyostimulation as part of a short strength-training program enhanced knee extensor strength and squat jump performance of basketball players.
    Publication International Journal of Sports Medicine
    Date Aug 2000
    URL http://www.ncbi.nlm.nih.gov/pubmed/10961520

    Tags:

    • Adult
    • Basketball
    • Electric Stimulation Therapy
    • Humans
    • Isometric Contraction
    • Knee Joint
    • Male
    • Movement
    • Muscle, Skeletal

    Attachments

    • Maffiuletti-Ijsm2000.pdf
    • PubMed Snapshot
  • The sites of neural adaptation induced by resistance training in humans

    Author Timothy J Carroll
    Author Stephan Riek
    Author Richard G Carson
    Abstract Although it has long been supposed that resistance training causes adaptive changes in the CNS, the sites and nature of these adaptations have not previously been identified. In order to determine whether the neural adaptations to resistance training occur to a greater extent at cortical or subcortical sites in the CNS, we compared the effects of resistance training on the electromyographic (EMG) responses to transcranial magnetic (TMS) and electrical (TES) stimulation. Motor evoked potentials (MEPs) were recorded from the first dorsal interosseous muscle of 16 individuals before and after 4 weeks of resistance training for the index finger abductors (n = 8), or training involving finger abduction-adduction without external resistance (n = 8). TMS was delivered at rest at intensities from 5 % below the passive threshold to the maximal output of the stimulator. TMS and TES were also delivered at the active threshold intensity while the participants exerted torques ranging from 5 to 60 % of their maximum voluntary contraction (MVC) torque. The average latency of MEPs elicited by TES was significantly shorter than that of TMS MEPs (TES latency = 21.5 ± 1.4 ms; TMS latency = 23.4 ± 1.4 ms; P < 0.05), which indicates that the site of activation differed between the two forms of stimulation. Training resulted in a significant increase in MVC torque for the resistance-training group, but not the control group. There were no statistically significant changes in the corticospinal properties measured at rest for either group. For the active trials involving both TMS and TES, however, the slope of the relationship between MEP size and the torque exerted was significantly lower after training for the resistance-training group (P < 0.05). Thus, for a specific level of muscle activity, the magnitude of the EMG responses to both forms of transcranial stimulation were smaller following resistance training. These results suggest that resistance training changes the functional properties of spinal cord circuitry in humans, but does not substantially affect the organisation of the motor cortex.
    Publication The Journal of Physiology
    Date 2002-10-15

    Attachments

    • neuralAdaptation.pdf
    • PubMed Central Link
  • The use of electrostimulation exercise in competitive sport

    Author Nicola A Maffiuletti
    Abstract After a brief introduction on electrostimulation methodology and applications in competitive sport for performance optimization, this technical report presents the principal effects of electrostimulation-induced resistance exercise on neuromuscular features. The advantages and limitations of this technique compared with those of voluntary exercise training are also discussed. Excellent concise scientific summary supporting EMS use in sport; only lacking in support for AR, which research subsequent to this summary found positive. The writer Nicola A. Maffiuletti, PhD, has been studying and researching neuromuscular electrophysiology for over 15 years, and has contributed more than 70 articles to the field, and authored dozens of studies published in peer-reviewed journals around the world. He is the Director, Neuromuscular Research Laboratory, Schulthess Clinic by Zurich, Switzerland.
    Publication International Journal of Sports Physiology and Performance
    Date Dec 2006
    URL http://www.ncbi.nlm.nih.gov/pubmed/19124897

    Attachments

    • Maffiuletti-ES-sport-Ijspp2006.pdf
    • PubMed Snapshot


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EMS use in Injury Rehabilitation

  • A modified neuromuscular electrical stimulation protocol for quadriceps strength training following anterior cruciate ligament reconstruction

    Author G Kelley Fitzgerald
    Author Sara R Piva
    Author James J Irrgang
    Abstract STUDY DESIGN: Randomized clinical trial, single-masked. OBJECTIVES: To determine the effectiveness of using a modified neuromuscular electrical stimulation (NMES) training program as an adjunct treatment for improving quadriceps strength and physical function in rehabilitation following anterior cruciate ligament reconstruction (ACLR). BACKGROUND: NMES training for quadriceps strengthening has previously been shown to be an effective adjunct treatment following ACLR when performed against isometric resistance using a dynamometer with the knee positioned in flexion. We developed a modified version of published NMES protocol because some patients have difficulty tolerating the existing protocol and many clinics may not have instrumented dynamometers. There is a need to determine the effectiveness of this modified protocol. METHODS AND MEASURES: Forty-three subjects who had undergone ACLR were randomly assigned to either a group that received (NMES group) or did not receive (comparison group) the NMES treatment in conjunction with their rehabilitation. Group means for quadriceps strength and self-reported measures of knee function were compared after 12 and 16 weeks of rehabilitation. The proportion of subjects in each group achieving clinical criteria to initiate ambulation without crutches, treadmill running, and agility training at selected times during rehabilitation were also compared. RESULTS: The NMES group demonstrated moderately greater quadriceps strength at 12 weeks (effect size, 0.48), and moderately higher levels of self-reported knee function at both 12 (effect size, 0.72) and 16 (effect size, 0.65) weeks of rehabilitation compared to the comparison group. A greater proportion of subjects in the NMES group achieved clinical criteria for advancing to agility training at 16 weeks. CONCLUSIONS: The modified NMES quadriceps training protocol can be a useful adjunct to ACLR rehabilitation programs, but the treatment effect is smaller than what has been reported in previous studies.
    Publication The Journal of Orthopaedic and Sports Physical Therapy
    Date Sep 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/14524508

    Tags:

    • Adult
    • Anterior Cruciate Ligament
    • Electric Stimulation Therapy
    • Female
    • Humans
    • Knee Injuries
    • Leg
    • Male
    • Muscle, Skeletal
    • Physical Therapy Modalities
    • Reconstructive Surgical Procedures
    • Treatment Outcome
    • Weight Lifting

    Attachments

    • A Modified Neuromuscular Electrical Stmulation Protocol for Quad Strength.pdf
    • PubMed Snapshot
  • Differences in Quadriceps Femoris Muscle Torque When Using a Clinical Electrical Stimulator Versus a Portable Electrical Stimulator

    Author Christian L Lyons
    Author Joel B Robb
    Author James J Irrgang
    Author G Kelley Fitzgerald
    Abstract Background and Purpose. There have been conflicting views and evidence reported in the literature concerning differences in muscle torque-generating capacities between clinical ("plug-in") console devices whose power source is provided by an electrical outlet (60 Hz, alternating current-driven) and portable electrical muscle stimulators (smaller, battery-operated stimulators). The purpose of this study was to compare the torque-generating capacity of the quadriceps femoris muscle during neuromuscular electrical stimulation (NMES) between a clinical neuromuscular electrical stimulator (VersaStim 380) and a portable neuromuscular electrical stimulator (Empi 300PV). Subjects. Forty volunteer subjects with no known knee, neurological, or cardiovascular pathology (22 male, 18 female) participated in the study. Methods. All subjects were tested with the clinical and portable stimulators on 2 separate days. Peak isometric torque of the quadriceps femoris muscle was measured using a Biodex dynamometer. Peak isometric quadriceps femoris muscle torque achieved during NMES and the average quadriceps femoris muscle torque integral produced over 10 NMES contractions were measured for each stimulator. Subjects also rated the amount of pain they experienced during the 10 NMES contractions using a numeric pain scale. Paired t tests were used to compare mean differences in measured variables between stimulator conditions. Results. There were no differences in the peak torque or numeric pain ratings during the electrically stimulated contractions between stimulator conditions. The Empi 300PV produced a greater average torque integral compared with the VersaStim 380 during 10 electrically stimulated contractions (Empi 300PV=988.6{+/-}330.4 N{middle dot}m-s, Versastim 380=822.7{+/-}292.6 N{middle dot}m-s). Discussion and Conclusion. The portable Empi 300PV stimulator produced comparable levels of average peak torque at comparable levels of discomfort to those produced by the VersaStim 380 clinical stimulator. The Empi 300PV maintained greater amounts of torque production during a 10-contraction training session compared with the VersaStim 380. Based on these data, we believe that the Empi 300PV has the potential to produce adequate levels of torque production for NMES quadriceps femoris muscle performance training. Further study is needed to determine the effectiveness of using the Empi 300PV for quadriceps femoris muscle performance training.
    Publication PHYS THER
    Date January 1, 2005
    URL http://www.ptjournal.org/cgi/content/abstract/85/1/44

    Attachments

    • HighWire Full Text PDF
    • HighWire Snapshot
  • Effects of two electrical stimulation frequencies in thigh muscle after knee surgery

    Author H Rebai
    Author V Barra
    Author A Laborde
    Author J-M Bonny
    Author G Poumarat
    Author J Coudert
    Abstract The purpose of this study was to compare the effects of two protocols of electrical stimulation combined with voluntary contractions on the recovery of thigh muscles after anterior cruciate ligament (ACL) surgery. Ten sportsmen with a mean age of 26 yrs were randomly assigned into two groups: a 80 Hz stimulated group (5 patients) and a 20 Hz stimulated group (5 patients). All patients received electrical stimulation of the quadriceps femoris, five days a week, for 12 weeks, and had a standard program of voluntary contractions. Muscle and fat volumes of the thigh were assessed using MRI before surgery and after 12 weeks of rehabilitation. Quadriceps and hamstring muscle strength were evaluated by isokinetic measurements. Twelve weeks after surgery, the quadriceps peak torque deficit in the operated limb with respect to the non operated limb at 180 degrees /s and 240 degrees /s was significantly (p < 0.05) less in the 20 Hz group than in the 80 Hz group. This difference was not confirmed when comparing the pre-surgery quadriceps peak torque of the operated limb with the post-surgery one. Subcutaneous fat volume was increased for the two groups at the post-surgery test. This increase was significantly (p < 0.05) greater for the 80 Hz group. Thigh muscle volume deficit was not significantly different between the two groups.
    Publication International Journal of Sports Medicine
    Date Nov 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/12439778

    Tags:

    • Adipose Tissue
    • Adult
    • Anterior Cruciate Ligament
    • Electric Stimulation Therapy
    • Humans
    • Knee Injuries
    • Magnetic Resonance Imaging
    • Male
    • Muscle, Skeletal
    • Random Allocation
    • Recovery of Function
    • Thigh
    • Torque

    Attachments

    • Effects of Two Electrical Stimulation Frequencies in Thigh Muscle After Knee Surgery.pdf
    • PubMed Snapshot
  • Electrical Stimulation Of The Quadriceps Muscle Group In Patients With Patellofemoral Pain Syndrome.

    Author Michael J Callaghan
    Abstract &apos;Patellofemoral Pain Syndrome (PFPS)&apos;- aka ‘chondromalacia patellae’- refers to the clinical presentation of anterior knee pain related to changes in the patellofemoral joint. PFPS is a common condition and presents a difficult problem for surgeons, therapists and patients alike. Pain can be brought on by prolonged sitting,by ascending and descending stairs, squatting, kneeling and by athletic activity. PFPS is considered to have an uncertain aetiology; one proposal is that PFPS may develop due to a generalized quadriceps weakness and wasting, decreased eccentric function, or differences in the activation patterns of the vastus medialis oblique (VMO) and vastus lateralis(VL). It is unknown if the quadriceps dysfunction causes the patellar pain, or the pain causes the dysfunction. Several long term follow up studies have indicated that overall outcome with non operative treatment of PFPS is generally good, with most patients rarely using analgesia and reporting subjective and displaying functional recovery. Nevertheless, one study found that 33% of patients still had symptoms or objective signs at seven years, and another revealed 25% still having significant symptoms at 20 years. Attempts have been made to correct extensor dysfunctions by differing methods of exercising the quadriceps. Unfortunately exercise, often increases patellar irritation with a subsequent worsening of patellofemoral pain. This study attempts to address this conundrum. Namely, how can the quadriceps be stimulated and exercised without concomitant irritation of the patellofemoral joint? The answer may lie in electrical stimulation of the quadriceps.
    University Centre for Rehabilitation Science, U. of Manchester, UK
    Date 2001

    Attachments

    • ELECTRICAL STIMULATION OF THE QUADRICEPS MUSCLE GROUP IN PATIENTS WITH PATELLOFEMORAL PAIN SYNDROME - Callaghan 2001 -Thesis.pdf
  • Examining Outcomes From Total Knee Arthroplasty And The Relationship Between Quadriceps Strength And Knee Function Over Time

    Author Yuri Yoshida
    Author Ryan L Mizner
    Author Dan K Ramsey
    Author Lynn Snyder-Mackler
    Publication Clinical biomechanics (Bristol, Avon)
    Date 2008 March
    URL http://www.pubmedcentral.nih.gov/articlerender.fcgi?
    artid=2293974

    Attachments

    • PubMed Central Full Text PDF
    • PubMed Central Snapshot
  • Quadriceps strength and the time course of functional recovery after total knee arthroplasty

    Author Ryan L Mizner
    Author Stephanie C Petterson
    Author Lynn Snyder-Mackler
    Abstract STUDY DESIGN: Prospective study with repeated measures. OBJECTIVES: The overall goal of this investigation was to describe the time course of recovery of impairments and function after total knee arthroplasty (TKA), as well as to provide direction for rehabilitation efforts. We hypothesized that quadriceps strength would be more strongly correlated with functional performance than knee flexion range of motion (ROM) or pain at all time periods studied before and after TKA. BACKGROUND: TKA is a very common surgery, but very little is known regarding the influence of impairments on functional limitations in this population. METHODS AND MEASURES: Forty subjects who underwent unilateral TKA followed by rehabilitation, including 6 weeks of outpatient physical therapy, were studied. Testing occurred at 5 time periods: preoperatively, and at 1, 2, 3, and 6 months after surgery. Test measures included quadriceps strength, knee ROM, timed up-and-go test, timed stair-climbing test, bodily pain, and general health and knee function questionnaires. RESULTS: Subjects experienced significant worsening of knee ROM, quadriceps strength, and performance on functional tests 1 month after surgery. Quadriceps strength went through the greatest decline of all the physical measures assessed and never matched the strength of the uninvolved limb. All measures underwent significant improvements following the 1-month test. Quadriceps strength was the most highly correlated measure associated with functional performance at all testing sessions. CONCLUSIONS: Functional measures underwent an expected decline early after TKA, but recovery was more rapid than anticipated and long-term outcomes were better than previously reported in the literature. The high correlation between quadriceps strength and functional performance suggests that improved postoperative quadriceps strengthening could be important to enhance the potential benefits of TKA.
    Publication The Journal of Orthopaedic and Sports Physical Therapy
    Date Jul 2005
    URL http://www.ncbi.nlm.nih.gov/pubmed/16108583

    Tags:

    • Aged
    • Aged, 80 and over
    • Analysis of Variance
    • Arthroplasty, Replacement, Knee
    • Female
    • Humans
    • Male
    • Middle Aged
    • Muscle, Skeletal
    • Osteoarthritis, Knee
    • Pain Measurement
    • Physical Therapy Modalities
    • Prospective Studies
    • Questionnaires
    • Range of Motion, Articular
    • Recovery of Function

    Attachments

    • July2005-RR-Mizner.pdf
    • PubMed Snapshot
    • Quadriceps Strength and the Time Course of Functional Recovery After Total Knee Arthroplasty - JOSPT – Journal of Orthopaedic & Sports Physical Therapy
  • Strength of the quadriceps femoris muscle and functional recovery after reconstruction of the anterior cruciate ligament. A prospective, randomized clinical trial of electrical stimulation

    Author L Snyder-Mackler
    Author A Delitto
    Author S L Bailey
    Author S W Stralka
    Abstract Immediately after reconstruction of the anterior cruciate ligament, 110 patients were randomly assigned to treatment with high-intensity neuromuscular electrical stimulation (thirty-one patients), high-level volitional exercise (thirty-four patients), low-intensity neuromuscular electrical stimulation (twenty-five patients), or combined high and low-intensity neuromuscular electrical stimulation (twenty patients). All treatment was performed isometrically with the knee in 65 degrees of flexion. All of the patients participated in an intensive program of closed-kinetic-chain exercise. After four weeks of treatment, the strength of the quadriceps femoris muscle and the kinematics of the knee during stance phase were measured. Quadriceps strength averaged 70 per cent or more of the strength on the uninvolved side in the two groups that were treated with high-intensity electrical stimulation (either alone or combined with low-intensity electrical stimulation), 57 per cent in the group that was treated with high-level volitional exercise, and 51 per cent in the group that was treated with low-intensity electrical stimulation. The kinematics of the knee joint were directly and significantly (p < 0.05) correlated with the strength of the quadriceps. There was a clinically and statistically significant (p < 0.05) difference in the recovery of the quadriceps and the gait parameters according to the type of operation that had been performed: the patients who had had reconstruction of the anterior cruciate ligament with use of an autologous patellar-ligament graft did poorly compared with the other patients.
    Publication The Journal of Bone and Joint Surgery. American Volume
    Date Aug 1995
    URL http://www.ncbi.nlm.nih.gov/pubmed/7642660

    Tags:

    • Adult
    • Anterior Cruciate Ligament
    • Electric Stimulation Therapy
    • Exercise Therapy
    • Female
    • Gait
    • Humans
    • Knee Joint
    • Male
    • Muscle Contraction
    • Muscle, Skeletal
    • Prospective Studies

    Attachments

    • PubMed Snapshot
  • Use of Electrical Stimulation to Enhance Recovery of Quadriceps Femoris Muscle Force Production in Patients Following Anterior Cruciate Ligament Reconstruction

    Author Lynn Snyder-Mackler
    Author Anthony Delitto
    Author Susan W Stralka
    Author Sherri L Bailey
    Abstract Background and Purpose. Electrical stimulation has been shown to be effective in aiding the recovery of quadriceps femoris muscle force production after anterior cruciate ligament reconstruction. The actual dosage of stimulation (training intensity) has not been well described. The purpose of this investigation was to establish a dose-response curve for electrical stimulation regimens designed to improve quadriceps femoris muscle recovery in patients after anterior cruciate ligament reconstruction. Subjects and Methods. We analyzed data from a subsample (n=52) of patients receiving electrical stimulation (N=110) who were involved in a large, multicenter randomized clinical trial investigating treatment strategies designed to enhance quadriceps femoris muscle recovery. Fifty-two subjects (40 male, 12 female), with an age range of 15 to 43 years ([IMG]f1.gif" ALT="X" BORDER="0">=25, SD=7), participated in 4 weeks of quadriceps femoris muscle training using either portable, battery-powered home stimulators or console stimulators designed for clinical use. Training intensities were monitored by logging the electrically elicited knee extension torque and expressing this torque as a percentage of the uninvolved quadriceps femoris muscles&apos; maximal voluntary contraction force. After the 4 weeks of training, isometric muscle torque was assessed and a dose-response curve was generated. The relationship between training intensity and quadriceps femoris muscle torque was assessed with Pearson Product-Moment Correlation Coefficients. Results. A significant, linear correlation was found between training intensity and quadriceps femoris muscle torque. Subjects training with console, clinical generators trained at higher intensities than those training with portable, battery-operated generators; such training resulted in higher quadriceps femoris muscle torque. Conclusion and Discussion. These results support the use of high-intensity electrical stimulation and do not support the use of low-intensity or battery-powered stimulators when the goal is recovery of quadriceps femoris muscle force production in the early phases of rehabilitation after anterior cruciate ligament surgery.
    Publication PHYS THER
    Date October 1, 1994
    URL http://www.ptjournal.org/cgi/content/abstract/74/10/901

    Attachments

    • HighWire Full Text PDF
    • HighWire Snapshot


Back to Top

Muscle Properties and EMS

  • A mathematical model that predicts the force-frequency relationship of human skeletal muscle

    Author Jun Ding
    Author Anthony S Wexler
    Author Stuart A Binder-Macleod
    Abstract In previous work we developed and validated a mathematical model that predicted force output from skeletal muscles subjected to six-pulse stimulation trains under isometric condition. The current study investigated the model&apos;s ability to predict force responses to longer stimulation trains under both nonfatigued and fatigued conditions. Using the six-pulse train model to predict the force produced by longer stimulation trains showed that the model was successful, but a modified parameter identification scheme was required. For most of the trains tested the model accounted for 95% of the variance in the experimental forces produced by stimulation trains, with mean frequencies from 12.5 to 100 HZ, train durations from 485 to 1000 ms, and number of pulses from 14 to 50 for both nonfatigued and fatigued muscles. The success of our mathematical model in predicting forces produced by stimulations with a wide range of frequencies, durations, and number of pulses implies great potential of the model for the identification of optimal activation patterns that should be used during functional electrical stimulation.
    Publication Muscle & Nerve
    Date Oct 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/12362412

    Tags:

    • Actins
    • Adult
    • Algorithms
    • Electric Stimulation
    • Friction
    • Humans
    • Isometric Contraction
    • Models, Statistical
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Myosins
    • Reproducibility of Results
    • Troponin

    Attachments

    • A mathematical model that predicts the force frequency relationship of skeletal muscle.pdf
    • PubMed Snapshot
  • Activation order of motor axons in electrically evoked contractions

    Author Roger M. Enoka
    Abstract No abstract.
    Publication Muscle & Nerve
    Date 2002
    URL http://dx.doi.org/10.1002/mus.10117

    Attachments

    • Enoka - Activation order of motor axons in electrically evoked contractions- Muscle Nerve 2002.pdf
  • Application of Muscle-Nerve Stimulation in Health and Disease

    Author Gerta Vrbova
    Author Olga Hudlicka
    Author Kristin Schaefer Centofanti
    Publisher Springer
    Date 2008

    Attachments

    • Amazon.com: Application of Muscle/Nerve Stimulation in Health and Disease (Advances in Muscle Research): Gerta Vrbová, Olga Hudlicka, Kristin Schaefer Centofanti: Books
    • Application of Muscle-Nerve Stimulation in Health and Disease (Springer, 2008).pdf
    • SpringerLink Snapshot
  • Clinical Electrophysiology: Electrotherapy and Electrophysiologic Testing

    Author Andrew J Robinson
    Author Lynn Snyder-Mackler
    Edition Third Edition
    Publisher Lippincott Williams & Wilkins
    Date 2007-09-01

    Attachments

    • Amazon.com Link
    • Clinical Electrophysiology.pdf
  • Comparison between electrically evoked and voluntary isometric contractions for biceps brachii muscle oxidative metabolism using near-infrared spectroscopy

    Author Makii Muthalib
    Author Marc Jubeau
    Author Guillaume Millet
    Author Nicola Maffiuletti
    Author Kazunori Nosaka
    Abstract Abstract This study compared voluntary (VOL) and electrically evoked isometric contractions by muscle stimulation (EMS) for changes in biceps brachii muscle oxygenation (tissue oxygenation index, ?TOI) and total haemoglobin concentration (?tHb = oxygenated haemoglobin + deoxygenated haemoglobin) determined by near-infrared spectroscopy. Twelve men performed EMS with one arm followed 24 h later by VOL with the contralateral arm, consisting of 30 repeated (1-s contraction, 1-s relaxation) isometric contractions at 30% of maximal voluntary contraction (MVC) for the first 60 s, and maximal intensity contractions thereafter (MVC for VOL and maximal tolerable current at 30 Hz for EMS) until MVC decreased ~30% of pre-exercise MVC. During the 30 contractions at 30% MVC, ?TOI decrease was significantly (P < 0.05) greater and ?tHb was significantly (P < 0.05) lower for EMS than VOL, suggesting that the metabolic demand for oxygen in EMS is greater than VOL at the same torque level. However, during maximal intensity contractions, although EMS torque (~40% of VOL) was significantly (P < 0.05) lower than VOL, ?TOI was similar and ?tHb was significantly (P < 0.05) lower for EMS than VOL towards the end, without significant differences between the two sessions in the recovery period. It is concluded that the oxygen demand of the activated biceps brachii muscle in EMS is comparable to VOL at maximal intensity.
    Publication European Journal of Applied Physiology
    Date 2009
    URL http://dx.doi.org/10.1007/s00421-009-1118-2

    Attachments

    • Preview Comparison between electrically evoked and voluntary isometric.pdf
    • SpringerLink Snapshot
  • Distribution of fibre sizes in human skeletal muscle. An enzyme histochemical study in m tibialis anterior

    Author K. HENRIKSSON-LARSEN
    Author J. FRIDEN
    Author M-L. WRETLING
    Abstract The aim of the study was to determine the fibre size distribution within the human m tibialis anterior. Ten-micron thick cross-sections of the whole muscle were enzyme histochemically stained for myofibrillar ATPase at pH 9.4. The cross-sectional area of 100 fibres with low (type 1) ATPase and high (type 2) ATPase activity was measured in three different regions (superficial, central and deep). Both the type 1 and type 2 fibres were found to be larger in the deep region than in the central or superficial regions. The variation in fibre size could not be explained by the cryofixation or cryo-embedding techniques used. The data suggest that muscle adaptation to physical demands may not only occur by means of variation in types and number of muscle fibres, but also by variation in fibre size over the muscle cross-section.
    Publication Acta Physiologica Scandinavica
    Date 1985
    URL http://dx.doi.org/10.1111/j.1748-1716.1985.tb07574.x

    Attachments

    • Wiley Interscience PDF
  • Effect of ageing on the electrical and mechanical properties of human soleus motor units activated by the H reflex and M wave

    Author G Scaglioni
    Author M V Narici
    Author N A Maffiuletti
    Author M Pensini
    Author A Martin
    Abstract This study was designed to investigate the effect of ageing on the mechanical and electromyographic (EMG) characteristics of the soleus motor units (MUs) activated by the maximal Hoffmann reflex (Hmax) and by the direct muscle compound action potential (Mmax). Eleven young (mean age 25 +/- 4 years) and ten elderly (mean age 73 +/- 5 years) males took part in this investigation. The senior group presented lower amplitudes of Mmax (-57 %, P < 0.001) and Hmax (-68 %, P < 0.001) waves compared to the younger population. These were associated with a depression of relative twitch torque of the plantar flexors. The average values of the Hmax/Mmax ratio did not statistically differ between the two populations, despite a tendency for lower values (~23 %) in the senior group. However, the older adults showed a greater relative amplitude of the sub-maximal M wave evoked at Hmax (MatHmax) than did the younger males (young 5 % vs. elderly 29 % of the Mmax, P < 0.01). This finding suggests an increased homogeneity between the excitability threshold of sensory and motor axons. The twitch torque at Hmax (PtH-M) was subsequently calculated by subtraction from the total twitch torque of the mechanical contamination associated with MatHmax. The resulting PtH-M was significantly lower in the elderly (-59 %, P < 0.001). Despite a discrepancy of 20 % between the two groups, the mechanical ratio (PtH-M/PtM; PtM, twitch tension related to the Mmax compound action potential), like the EMG ratio, did not statistically differ between the young and older individuals. Nevertheless, the senior subjects exhibited a higher twitch/EMG ratio for the reflexively activated MUs (PtH-M/Hmax) than the younger individuals (+40 %, P < 0.05). This finding suggests an on-going neuromuscular remodelling, resulting in an increased innervation ratio. The neural rearrangement may be viewed as a compensatory adaptation of the motor system to preserve the mechanical efficiency of the surviving MUs, despite the age-related impairment of the segmental reflex system. This phenomenon is confirmed by the maintenance, with senescence, of the approximately constant values of the twitch/EMG ratio for the entire motor pool (PtM/Mmax).
    Publication The Journal of Physiology
    Date Apr 15, 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/12588895

    Tags:

    • Action Potentials
    • Adult
    • Aged
    • Aging
    • Electric Stimulation
    • Electromyography
    • Electrophysiology
    • Female
    • H-Reflex
    • Humans
    • Male
    • Motor Neurons
    • Muscle Contraction
    • Muscle, Skeletal

    Attachments

    • PubMed Snapshot
  • Effect of cycling cadence on contractile and neural properties of knee extensors

    Author R Lepers
    Author G Y Millet
    Author N A Maffiuletti
    Abstract PURPOSE: This study investigated the effect of prior prolonged cycling exercise performed at different cadences on subsequent neuromuscular characteristics. METHODS: Eight well-trained triathletes sustained 80% of their maximal aerobic power during 30 min at three cadences: the freely chosen cadence (FCC), FCC-20%, and FCC+20%. Maximal isometric and concentric (120 degrees x s(-1) and 240 degrees x s(-1)) torques were recorded before and after the exercise. Central activation, neural (M-wave), and contractile (isometric muscular twitch) parameters of quadriceps muscle were also analyzed by electrical stimulation of the femoral nerve. RESULTS: Reductions in maximal isometric (P < 0.01) and concentric torques at 120 degrees x s(-1) (P < 0.05) were found after exercise. Central activation levels fell significantly (P < 0.05) by 13-16% depending on the pedaling rate. Although the M-wave did not significantly change after exercise, the ratio EMG RMS/M-wave amplitude decreased significantly (P < 0.01) on both vastus lateralis and vastus medialis muscles for FCC-20% and FCC but not for FCC+20%. Significant decreases in maximal twitch tension (P < 0.01), maximal rate of twitch development (P < 0.01), and time to half relaxation (P < 0.01) were observed postexercise with no effect of cadence. CONCLUSIONS: These findings suggest that force reduction after prolonged cycling is attributable to both central and peripheral factors but is not influenced by the pedaling rate in a range of FCC +/- 20%.
    Publication Medicine and Science in Sports and Exercise
    Date Nov 2001
    URL http://www.ncbi.nlm.nih.gov/pubmed/11689739

    Tags:

    • Adult
    • Bicycling
    • Electric Stimulation
    • Electromyography
    • Exercise
    • Humans
    • Knee
    • Male
    • Muscle Contraction
    • Muscle Fibers, Skeletal
    • Muscle, Skeletal
    • Torque

    Attachments

    • PubMed Snapshot
  • Electrical and mechanical H(max)-to-M(max) ratio in power- and endurance-trained athletes

    Author N A Maffiuletti
    Author A Martin
    Author N Babault
    Author M Pensini
    Author B Lucas
    Author M Schieppati
    Abstract The aim of this study was to compare the mechanical and electromyographic (EMG) characteristics of soleus motor units activated during maximal H reflex and direct M response among subjects with different histories of physical activity. Power-trained athletes produced stronger twitches, with a higher rate of twitch tension buildup and relaxation, than their endurance counterparts for both maximal H-reflex and maximal M-wave responses. The maximal H-reflex-to-maximal M-wave ratios for both force output (twitch) and EMG wave amplitude were significantly lower in power-trained than endurance-trained athletes. However, power-trained athletes exhibited a significantly greater twitch-to-EMG ratio for the reflexly activated motor units with respect to the entire motor pool, whereas endurance-trained athletes had comparable twitch-to-EMG ratios for both reflexly and directly activated units. Power training increases the force output of the whole ensemble of the motor units, thereby compensating for the lower efficacy of the reflex transmission between Ia spindle afferent input and soleus alpha-motoneuron. On the other hand, the lower level of force evoked by the reflexly activated units in endurance-trained athletes is associated with a greater motor pool reflex excitability. Therefore, endurance-trained athletes produce the necessary force by recruitment of more slow-twitch units than do other subjects for comparable levels of force and type of task.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Jan 2001
    URL http://www.ncbi.nlm.nih.gov/pubmed/11133886

    Tags:

    • Adult
    • Electric Stimulation
    • Electromyography
    • H-Reflex
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Relaxation
    • Muscle, Skeletal
    • Physical Education and Training
    • Physical Endurance
    • Reference Values
    • Tibial Nerve

    Attachments

    • PubMed Snapshot
  • Functional heterogeneity of mammalian single muscle fibres: do myosin isoforms tell the whole story?

    Author R Bottinelli
    Abstract The large amount of data published in the last 10-15 years indicate that myosin isoforms are the major determinant of the large functional heterogeneity of the key contractile and biochemical properties of skeletal muscle fibres, including velocity of shortening, ATP consumption and power. Recent evidences are difficult to reconcile with such an idea and suggest that the properties of muscle fibres that are likely to depend on myosin, such as velocity of shortening, can change without a change in myosin isoform. That a given myosin isoform can modify its properties without shifting to another isoform is confirmed by some analyses of isolated myosin in vitro. The present review is mainly focused on findings that challenge the role of myosin isoforms in determining the functional heterogeneity of skeletal muscle. The work also reports on potential mechanisms behind such changes in myosin function independent of a shift in myosin isoform: the coexistence of different myosin heavy chain (MHC) isoforms in the same fibre, the existence of as yet undetected MHC isoforms, myosin light chain isoforms, post-translational modifications of myosin, the role of other myofibrillar proteins, geometry of the sarcomere and the myosin concentration in single fibres.
    Publication Pflügers Archiv: European Journal of Physiology
    Date Oct 2001
    URL http://www.ncbi.nlm.nih.gov/pubmed/11692261

    Tags:

    • Animals
    • Humans
    • Muscle Fibers, Skeletal
    • Myosin Heavy Chains
    • Myosins
    • Protein Isoforms
    • Sarcomeres

    Attachments

    • Functional heterogeneity of mammalian single muscle fibres do myosin isoforms tell the whole story.pdf
    • PubMed Snapshot
    • SpringerLink - Journal Article
  • Human skeletal muscle fibres: molecular and functional diversity

    Author R. Bottinelli
    Author C. Reggiani
    Abstract Contractile and energetic properties of human skeletal muscle have been studied for many years in vivo in the body. It has been, however, difficult to identify the specific role of muscle fibres in modulating muscle performance. Recently it has become possible to dissect short segments of single human muscle fibres from biopsy samples and make them work in nearly physiologic conditions in vitro. At the same time, the development of molecular biology has provided a wealth of information on muscle proteins and their genes and new techniques have allowed analysis of the protein isoform composition of the same fibre segments used for functional studies. In this way the histological identification of three main human muscle fibre types (I, IIA and IIX, previously called IIB) has been followed by a precise description of molecular composition and functional and biochemical properties. It has become apparent that the expression of different protein isoforms and therefore the existence of distinct muscle fibre phenotypes is one of the main determinants of the muscle performance in vivo. The present review will first describe the mechanisms through which molecular diversity is generated and how fibre types can be identified on the basis of structural and functional characteristics. Then the molecular and functional diversity will be examined with regard to (1) the myofibrillar apparatus; (2) the sarcolemma and the sarcoplasmic reticulum; and (3) the metabolic systems devoted to producing ATP. The last section of the review will discuss the advantage that fibre diversity can offer in optimizing muscle contractile performance. Corresponding author. Tel.: +39-0382-507257; fax: +39-0382-507664; email: r.bottinelli@unipv.it
    Publication Progress in Biophysics and Molecular Biology
    Date May 2000
    URL http://www.sciencedirect.com/science?
    _ob=ArticleURL&…

    Attachments

    • Bottinelli-review MHC.pdf
    • ScienceDirect Snapshot
  • Muscle strength and its development. New perspectives

    Author R M Enoka
    Abstract Skeletal muscle undergoes substantial adaptation when it is subjected to a strength training regimen. At one extreme, these effects are manifested as profound morphological changes, such as those exemplified by bodybuilders. However, it is possible to increase strength without any change in muscle size. This dissociation underscores the notion that strength is not solely a property of muscle but rather it is a property of the motor system. The nervous system seems to be of paramount importance for the expression and development of strength. Indeed, it is probable that increases in strength can be achieved without morphological changes in muscle but not without neural adaptations. This review focuses on the role of the nervous system in the development of strength. In the strength literature, 3 topics exemplify the importance of the nervous system in strength development. These 3 topics are considered in detail in the review: electromyostimulation, cross-training effects, and EMG-force relationships. Evidence is presented from several different paradigms emphasising the significant contribution of neural mechanisms to the gains in strength with short term training. Although little is known about the specific neural mechanisms associated with strength training adaptations, the literature emphasises that the measure of human performance known as strength can be influenced by a variety of neurophysiological processes.
    Publication Sports Medicine (Auckland, N.Z.)
    Date Sep 1988
    URL http://www.ncbi.nlm.nih.gov/pubmed/3055145

    Tags:

    • Electric Stimulation
    • Electromyography
    • Humans
    • Isometric Contraction
    • Motor Endplate
    • Muscle Contraction
    • Muscles
    • Physical Education and Training

    Attachments

    • PubMed Snapshot
  • Nerve-Muscle Interaction

    Author Gerta Vrbova
    Contributor Te Gordon
    Contributor Rosem Jones
    Edition 2nd
    Place London
    Publisher Chapman & Hall
    Date 1995
    # of Pages 256

    Tags:

    • innervat
    • Muscles
    • Myoneural junct
    • Neuromuscular disea
    • Neuromuscular Junct
    • Neuromuscular transmiss
    • Neurophysiol

    Attachments

    • Nerve -Muscle Interaction chap.5 - bibliography.pdf
    • Nerve -Muscle Interaction chap.5 - Vrbova, Gordon, Jones - 1995.pdf
  • Neuromechanics of human movement

    Author Roger Enoka
    Abstract (from Amazon) Drawing on the disciplines of neurophysiology and physics, Neuromechanics of Human Movement, Fourth Edition, explores how the nervous system controls the actions of muscles to produce human motion in relation to biomechanical principles. This contemporary approach is much different from the traditional approach, which focuses solely on mechanics and does not consider the role of the sensory system in the control of human movement. Neuromechanics of Human Movement, Fourth Edition, provides a scientific foundation to the study of human movement, and as such it uses precise terms and definitions when discussing ideas and utilizing the international metric system (SI). Readers will find an appendix that helps in identifying the SI metric units as well as other learning tools, including a glossary of terms and two other appendixes that cover conversion factors and equations. Throughout the text, the content is visually reinforced with more than 750 illustrations, many of which are new or upgraded from the previous edition and include specific illustrations of the neuromechanics involved in sport and rehabilitation movements. Finally, the text contains more than 1,500 updated references and suggested reading lists for each chapter. To further enhance this fourth edition, significant content updates have been made to ensure the latest information is presented for both research and clinical environments: * New coverage regarding electromyography (EMG) that demonstrates the connection between the nervous system and the muscle by measuring the activation signal, allowing readers to better understand how motion is activated * Additional examples that underscore recent research developments in reaching and grasping activities for rehabilitation * In-depth coverage of the motor system that addresses excitable membranes, muscle and motor units, and voluntary movement * Expanded discussion of neuromuscular system adaptations to the aging process * Neuromuscular system adaptations with particular application to rehabilitation To encourage a comprehensive learning experience, this updated edition follows a logical progression where each part builds on the material from the previous section. It begins with an introduction to the biomechanical terms and concepts commonly used to describe movement, focusing on the relation between force and motion. Once readers have grasped the basic laws of motion, the text continues by considering the essential neurophysiological concepts that help to explain movement produced by the nervous system and muscle. The author uses a "bottom-up" approach for this explanation that begins with the principles of electricity and extends up to connections within the cerebral cortex. This approach encompasses the essentials of electricity responsible for the excitability of cell membranes and explains the relations between spinal neurons and muscle fibers. The third and final part of the text concludes by describing the ways in which the motor system adapts to various types of physical stress. These adapative capabilities include altering core temperature, phenomena such as strength and power training, adaptations that occur after periods of reduced activity, motor recovery from injury; and changes that occur with aging. Readers will understand how acute adjustments can be made to the motor system through interventions such as warm-up, flexibility, muscle soreness, and muscle fatigue. Author Roger M. Enoka, PhD, is a professor and chair in the department of integrative physiology at the University of Colorado at Boulder. He is also a professor in the Health Sciences Center, department of medicine, geriatrics, at the University of Colorado. Previously, Enoka was a biomechanist in the department of biomedical engineering at the Cleveland Clinic Foundation and a professor in the department of physiology at the University of Arizona. For more than 30 years, Enoka has focused his research and teaching on the combination of biomechanics and neurophysiology of movement. He conducts an interdisciplinary research program, which has received continuous funding by the National Institutes of Health for almost two decades. Internationally known for his achievements as a teacher and researcher, Enoka is the author of about 350 journal articles, books, chapters, reviews, and abstracts related to his research. He is also a reviewer for numerous journals and serves on the editorial board for the Journal of Applied Physiology, Journal of Electromyography and Kinesiology, Motor Control, Sports Medicine, Muscle and Nerve, and the Scandinavian Journal of Medicine and Science in Sports. Enoka&apos;s professional affiliations include the American College of Sports Medicine, the American Physiological Society, International Society of Biomechanics, and the Society for Neuroscience. He is a former member of the Advisory Panel on Research for the American Physical Therapy Association and the Respiratory and Applied Physiology Study Section of the National Institutes of Health. Enoka is also a past president and current member of the American Society of Biomechanics.
    Edition 4. ed.
    Place Champaign IL [u.a.]
    Publisher Human Kinetics
    Date 2008
  • Neuromuscular fatigue during a long-duration cycling exercise

    Author Romuald Lepers
    Author Nicola A Maffiuletti
    Author Ludovic Rochette
    Author Julien Brugniaux
    Author Guillaume Y Millet
    Abstract The effects of prolonged cycling on neuromuscular parameters were studied in nine endurance-trained subjects during a 5-h exercise sustained at 55% of the maximal aerobic power. Torque during maximal voluntary contraction (MVC) of the quadriceps muscle decreased progressively throughout the exercise (P < 0.01) and was 18% less at the end of exercise compared with the preexercise value. Peak twitch torque, contraction time, and total area of mechanical response decreased significantly (P < 0.05) after the first hour of exercise. In contrast, changes in M-wave characteristics were significant only after the fourth hour of the exercise. Significant reductions (P < 0.05) in electromyographic activity normalized to the M wave occurred after the first hour for the vastus lateralis muscle but only at the end of the exercise for the vastus medialis muscle. Muscle activation level, assessed by the twitch interpolation technique, decreased by 8% (P < 0.05) at the end of the exercise. The results suggest that the time course is such that the contractile properties are significantly altered after the first hour, whereas excitability and central drive are more impaired toward the latter stages of the 5-h cycling exercise.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Apr 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/11896014

    Tags:

    • Adult
    • Bicycling
    • Electromyography
    • Exercise
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Physical Endurance
    • Thigh
    • Torque

    Attachments

    • PubMed Snapshot
  • Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men

    Author Juha P Ahtiainen
    Author Arto Pakarinen
    Author Markku Alen
    Author William J Kraemer
    Author Keijo Häkkinen
    Abstract Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magnetic resonance imaging (MRI) were measured at months 0, 3, and 6. The 2 hypertrophic training protocols used in training for the leg extensors (leg presses and squats with 10RM sets) were also examined in the laboratory conditions at months 0, 3, and 6. The exercise protocols were similar with regard to the total volume of work (loads x sets x reps), but differed with regard to the intensity and the length of rest between the sets (higher intensity and longer rest of 5 minutes vs. somewhat lower intensity but shorter rest of 2 minutes). Before and immediately after the protocols, maximal isometric force and electromyographic (EMG) activity of the leg extensors were measured and blood samples were drawn for determination of serum T, FT, C, and growth hormone (GH) concentrations and blood lactate. Both protocols before the experimental training period (month 0) led to large acute increases (p < 0.05-0.001) in serum T, FT, C , and GH concentrations, as well as to large acute decreases (p < 0.05-0.001) in maximal isometric force and EMG activity. However, no significant differences were observed between the protocols. Significant increases of 7% in maximal isometric force, 16% in the right leg 1RM, and 4% in the muscle CSA of the quadriceps femoris were observed during the 6-month strength-training period. However, both 3-month training periods performed with either the longer or the shorter rest periods between the sets resulted in similar gains in muscle mass and strength. No statistically significant changes were observed in basal hormone concentrations or in the profiles of acute hormonal responses during the entire 6-month experimental training period. The present study indicated that, within typical hypertrophic strength-training protocols used in the present study, the length of the recovery times between the sets (2 vs. 5 minutes) did not have an influence on the magnitude of acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass in previously strength-trained men.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Aug 2005
    URL http://www.ncbi.nlm.nih.gov/pubmed/16095405

    Tags:

    • Adult
    • Cross-Over Studies
    • Diet
    • Electromyography
    • Human Growth Hormone
    • Humans
    • Hydrocortisone
    • Isometric Contraction
    • Leg
    • Male
    • Muscle, Skeletal
    • Physical Education and Training
    • Rest
    • Testosterone

    Attachments

    • PubMed Snapshot
  • The effects of a prolonged running exercise on strength characteristics

    Author R Lepers
    Author M L Pousson
    Author N A Maffiuletti
    Author A Martin
    Author J Van Hoecke
    Abstract The aim of this study was to examine concentric, isometric, and eccentric strength reductions in the quadriceps muscle following a prolonged running exercise. Before and after a 2 h run (28.4+/-1.4 km) peak torque (PT) of the knee extensors at angular velocities of -120, -90, -60, 0, 60, 120, 180, 240 degrees x s(-1) using an isokinetic dynamometer, electromyographic (EMG) activity of the vastus lateralis (VL) and vastus medialis (VM) muscles and height of a counter movement jump were recorded in twelve well-trained triathletes. Counter movement jump performances decreased by 10% and PT values were all significantly lower (p < 0.01) at each angular velocity following the run. The torque loss was significantly (p < 0.01) greater under eccentric contractions (from 18 to 21%) than under concentric ones (from 11 to 14%). EMG activity (RMS) was lower in both VL and VM muscles after the 2 h run but no difference existed in RMS losses between concentric and eccentric contractions. The present results demonstrate that 1) a prolonged running exercise more greatly affects eccentric force production in the quadriceps muscle, and 2) this specificity seems to be due to an impairment of the muscular contractile mechanism rather than a modification to the neural input.
    Publication International Journal of Sports Medicine
    Date May 2000
    URL http://www.ncbi.nlm.nih.gov/pubmed/10853699

    Tags:

    • Adult
    • Biomechanics
    • Electromyography
    • Ergometry
    • Humans
    • Knee
    • Male
    • Movement
    • Muscle Contraction
    • Muscle, Skeletal
    • Physical Endurance
    • Running
    • Torque

    Attachments

    • PubMed Snapshot
  • The relative contribution to the plantar-flexor torque of the soleus motor units activated by the H reflex and M response in humans

    Author N A Maffiuletti
    Author A Martin
    Author J Van Hoecke
    Author M Schieppati
    Abstract This study proposes a method of quantifying the relative contribution to the plantar-flexor torque of soleus H and M responses evoked by tibial nerve stimulation. For ten subjects, the amplitude of the twitch produced by the H wave was plotted against the corresponding potential, for stimuli producing H without M (i.e. in the ascending portion of the H-recruitment curve). It was then assumed that the contribution of H to twitches produced by M plus H was similar for similar H waves on the curve-descending portion. Hence, the contribution of M was estimated, for the range of M waves including those accompanying H(max). The estimated mechanical contributions of H and M wave increase linearly with their potentials, the slope of the relationship being greater for H than M. The interpretation of this finding is discussed. A simple formula for assessing the contribution of the H wave to the twitch torque is given.
    Publication Neuroscience Letters
    Date Jul 14, 2000
    URL http://www.ncbi.nlm.nih.gov/pubmed/10876077

    Tags:

    • Action Potentials
    • Adult
    • Electric Stimulation
    • Electromyography
    • H-Reflex
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Fibers, Fast-Twitch
    • Muscle Fibers, Slow-Twitch
    • Muscle, Skeletal
    • Tibial Nerve
    • Torque

    Attachments

    • PubMed Snapshot


Back to Top

Non EMS

  • A mathematical model that predicts the force-frequency relationship of human skeletal muscle

    Author Jun Ding
    Author Anthony S Wexler
    Author Stuart A Binder-Macleod
    Abstract In previous work we developed and validated a mathematical model that predicted force output from skeletal muscles subjected to six-pulse stimulation trains under isometric condition. The current study investigated the model&apos;s ability to predict force responses to longer stimulation trains under both nonfatigued and fatigued conditions. Using the six-pulse train model to predict the force produced by longer stimulation trains showed that the model was successful, but a modified parameter identification scheme was required. For most of the trains tested the model accounted for 95% of the variance in the experimental forces produced by stimulation trains, with mean frequencies from 12.5 to 100 HZ, train durations from 485 to 1000 ms, and number of pulses from 14 to 50 for both nonfatigued and fatigued muscles. The success of our mathematical model in predicting forces produced by stimulations with a wide range of frequencies, durations, and number of pulses implies great potential of the model for the identification of optimal activation patterns that should be used during functional electrical stimulation.
    Publication Muscle & Nerve
    Date Oct 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/12362412

    Tags:

    • Actins
    • Adult
    • Algorithms
    • Electric Stimulation
    • Friction
    • Humans
    • Isometric Contraction
    • Models, Statistical
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Myosins
    • Reproducibility of Results
    • Troponin

    Attachments

    • A mathematical model that predicts the force frequency relationship of skeletal muscle.pdf
    • PubMed Snapshot
  • Activation order of motor axons in electrically evoked contractions

    Author Roger M. Enoka
    Abstract No abstract.
    Publication Muscle & Nerve
    Date 2002
    URL http://dx.doi.org/10.1002/mus.10117

    Attachments

    • Enoka - Activation order of motor axons in electrically evoked contractions- Muscle Nerve 2002.pdf
  • Application of Muscle-Nerve Stimulation in Health and Disease

    Author Gerta Vrbova
    Author Olga Hudlicka
    Author Kristin Schaefer Centofanti
    Publisher Springer
    Date 2008

    Attachments

    • Amazon.com: Application of Muscle/Nerve Stimulation in Health and Disease (Advances in Muscle Research): Gerta Vrbová, Olga Hudlicka, Kristin Schaefer Centofanti: Books
    • Application of Muscle-Nerve Stimulation in Health and Disease (Springer, 2008).pdf
    • SpringerLink Snapshot
  • Clinical Electrophysiology: Electrotherapy and Electrophysiologic Testing

    Author Andrew J Robinson
    Author Lynn Snyder-Mackler
    Edition Third Edition
    Publisher Lippincott Williams & Wilkins
    Date 2007-09-01

    Attachments

    • Amazon.com Link
    • Clinical Electrophysiology.pdf
  • Comparison between electrically evoked and voluntary isometric contractions for biceps brachii muscle oxidative metabolism using near-infrared spectroscopy

    Author Makii Muthalib
    Author Marc Jubeau
    Author Guillaume Millet
    Author Nicola Maffiuletti
    Author Kazunori Nosaka
    Abstract Abstract This study compared voluntary (VOL) and electrically evoked isometric contractions by muscle stimulation (EMS) for changes in biceps brachii muscle oxygenation (tissue oxygenation index, ?TOI) and total haemoglobin concentration (?tHb = oxygenated haemoglobin + deoxygenated haemoglobin) determined by near-infrared spectroscopy. Twelve men performed EMS with one arm followed 24 h later by VOL with the contralateral arm, consisting of 30 repeated (1-s contraction, 1-s relaxation) isometric contractions at 30% of maximal voluntary contraction (MVC) for the first 60 s, and maximal intensity contractions thereafter (MVC for VOL and maximal tolerable current at 30 Hz for EMS) until MVC decreased ~30% of pre-exercise MVC. During the 30 contractions at 30% MVC, ?TOI decrease was significantly (P < 0.05) greater and ?tHb was significantly (P < 0.05) lower for EMS than VOL, suggesting that the metabolic demand for oxygen in EMS is greater than VOL at the same torque level. However, during maximal intensity contractions, although EMS torque (~40% of VOL) was significantly (P < 0.05) lower than VOL, ?TOI was similar and ?tHb was significantly (P < 0.05) lower for EMS than VOL towards the end, without significant differences between the two sessions in the recovery period. It is concluded that the oxygen demand of the activated biceps brachii muscle in EMS is comparable to VOL at maximal intensity.
    Publication European Journal of Applied Physiology
    Date 2009
    URL http://dx.doi.org/10.1007/s00421-009-1118-2

    Attachments

    • Preview Comparison between electrically evoked and voluntary isometric.pdf
    • SpringerLink Snapshot
  • Distribution of fibre sizes in human skeletal muscle. An enzyme histochemical study in m tibialis anterior

    Author K. HENRIKSSON-LARSEN
    Author J. FRIDEN
    Author M-L. WRETLING
    Abstract The aim of the study was to determine the fibre size distribution within the human m tibialis anterior. Ten-micron thick cross-sections of the whole muscle were enzyme histochemically stained for myofibrillar ATPase at pH 9.4. The cross-sectional area of 100 fibres with low (type 1) ATPase and high (type 2) ATPase activity was measured in three different regions (superficial, central and deep). Both the type 1 and type 2 fibres were found to be larger in the deep region than in the central or superficial regions. The variation in fibre size could not be explained by the cryofixation or cryo-embedding techniques used. The data suggest that muscle adaptation to physical demands may not only occur by means of variation in types and number of muscle fibres, but also by variation in fibre size over the muscle cross-section.
    Publication Acta Physiologica Scandinavica
    Date 1985
    URL http://dx.doi.org/10.1111/j.1748-1716.1985.tb07574.x

    Attachments

    • Wiley Interscience PDF
  • Effect of ageing on the electrical and mechanical properties of human soleus motor units activated by the H reflex and M wave

    Author G Scaglioni
    Author M V Narici
    Author N A Maffiuletti
    Author M Pensini
    Author A Martin
    Abstract This study was designed to investigate the effect of ageing on the mechanical and electromyographic (EMG) characteristics of the soleus motor units (MUs) activated by the maximal Hoffmann reflex (Hmax) and by the direct muscle compound action potential (Mmax). Eleven young (mean age 25 +/- 4 years) and ten elderly (mean age 73 +/- 5 years) males took part in this investigation. The senior group presented lower amplitudes of Mmax (-57 %, P < 0.001) and Hmax (-68 %, P < 0.001) waves compared to the younger population. These were associated with a depression of relative twitch torque of the plantar flexors. The average values of the Hmax/Mmax ratio did not statistically differ between the two populations, despite a tendency for lower values (~23 %) in the senior group. However, the older adults showed a greater relative amplitude of the sub-maximal M wave evoked at Hmax (MatHmax) than did the younger males (young 5 % vs. elderly 29 % of the Mmax, P < 0.01). This finding suggests an increased homogeneity between the excitability threshold of sensory and motor axons. The twitch torque at Hmax (PtH-M) was subsequently calculated by subtraction from the total twitch torque of the mechanical contamination associated with MatHmax. The resulting PtH-M was significantly lower in the elderly (-59 %, P < 0.001). Despite a discrepancy of 20 % between the two groups, the mechanical ratio (PtH-M/PtM; PtM, twitch tension related to the Mmax compound action potential), like the EMG ratio, did not statistically differ between the young and older individuals. Nevertheless, the senior subjects exhibited a higher twitch/EMG ratio for the reflexively activated MUs (PtH-M/Hmax) than the younger individuals (+40 %, P < 0.05). This finding suggests an on-going neuromuscular remodelling, resulting in an increased innervation ratio. The neural rearrangement may be viewed as a compensatory adaptation of the motor system to preserve the mechanical efficiency of the surviving MUs, despite the age-related impairment of the segmental reflex system. This phenomenon is confirmed by the maintenance, with senescence, of the approximately constant values of the twitch/EMG ratio for the entire motor pool (PtM/Mmax).
    Publication The Journal of Physiology
    Date Apr 15, 2003
    URL http://www.ncbi.nlm.nih.gov/pubmed/12588895

    Tags:

    • Action Potentials
    • Adult
    • Aged
    • Aging
    • Electric Stimulation
    • Electromyography
    • Electrophysiology
    • Female
    • H-Reflex
    • Humans
    • Male
    • Motor Neurons
    • Muscle Contraction
    • Muscle, Skeletal

    Attachments

    • PubMed Snapshot
  • Effect of cycling cadence on contractile and neural properties of knee extensors

    Author R Lepers
    Author G Y Millet
    Author N A Maffiuletti
    Abstract PURPOSE: This study investigated the effect of prior prolonged cycling exercise performed at different cadences on subsequent neuromuscular characteristics. METHODS: Eight well-trained triathletes sustained 80% of their maximal aerobic power during 30 min at three cadences: the freely chosen cadence (FCC), FCC-20%, and FCC+20%. Maximal isometric and concentric (120 degrees x s(-1) and 240 degrees x s(-1)) torques were recorded before and after the exercise. Central activation, neural (M-wave), and contractile (isometric muscular twitch) parameters of quadriceps muscle were also analyzed by electrical stimulation of the femoral nerve. RESULTS: Reductions in maximal isometric (P < 0.01) and concentric torques at 120 degrees x s(-1) (P < 0.05) were found after exercise. Central activation levels fell significantly (P < 0.05) by 13-16% depending on the pedaling rate. Although the M-wave did not significantly change after exercise, the ratio EMG RMS/M-wave amplitude decreased significantly (P < 0.01) on both vastus lateralis and vastus medialis muscles for FCC-20% and FCC but not for FCC+20%. Significant decreases in maximal twitch tension (P < 0.01), maximal rate of twitch development (P < 0.01), and time to half relaxation (P < 0.01) were observed postexercise with no effect of cadence. CONCLUSIONS: These findings suggest that force reduction after prolonged cycling is attributable to both central and peripheral factors but is not influenced by the pedaling rate in a range of FCC +/- 20%.
    Publication Medicine and Science in Sports and Exercise
    Date Nov 2001
    URL http://www.ncbi.nlm.nih.gov/pubmed/11689739

    Tags:

    • Adult
    • Bicycling
    • Electric Stimulation
    • Electromyography
    • Exercise
    • Humans
    • Knee
    • Male
    • Muscle Contraction
    • Muscle Fibers, Skeletal
    • Muscle, Skeletal
    • Torque

    Attachments

    • PubMed Snapshot
  • Electrical and mechanical H(max)-to-M(max) ratio in power- and endurance-trained athletes

    Author N A Maffiuletti
    Author A Martin
    Author N Babault
    Author M Pensini
    Author B Lucas
    Author M Schieppati
    Abstract The aim of this study was to compare the mechanical and electromyographic (EMG) characteristics of soleus motor units activated during maximal H reflex and direct M response among subjects with different histories of physical activity. Power-trained athletes produced stronger twitches, with a higher rate of twitch tension buildup and relaxation, than their endurance counterparts for both maximal H-reflex and maximal M-wave responses. The maximal H-reflex-to-maximal M-wave ratios for both force output (twitch) and EMG wave amplitude were significantly lower in power-trained than endurance-trained athletes. However, power-trained athletes exhibited a significantly greater twitch-to-EMG ratio for the reflexly activated motor units with respect to the entire motor pool, whereas endurance-trained athletes had comparable twitch-to-EMG ratios for both reflexly and directly activated units. Power training increases the force output of the whole ensemble of the motor units, thereby compensating for the lower efficacy of the reflex transmission between Ia spindle afferent input and soleus alpha-motoneuron. On the other hand, the lower level of force evoked by the reflexly activated units in endurance-trained athletes is associated with a greater motor pool reflex excitability. Therefore, endurance-trained athletes produce the necessary force by recruitment of more slow-twitch units than do other subjects for comparable levels of force and type of task.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Jan 2001
    URL http://www.ncbi.nlm.nih.gov/pubmed/11133886

    Tags:

    • Adult
    • Electric Stimulation
    • Electromyography
    • H-Reflex
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Relaxation
    • Muscle, Skeletal
    • Physical Education and Training
    • Physical Endurance
    • Reference Values
    • Tibial Nerve

    Attachments

    • PubMed Snapshot
  • Functional heterogeneity of mammalian single muscle fibres: do myosin isoforms tell the whole story?

    Author R Bottinelli
    Abstract The large amount of data published in the last 10-15 years indicate that myosin isoforms are the major determinant of the large functional heterogeneity of the key contractile and biochemical properties of skeletal muscle fibres, including velocity of shortening, ATP consumption and power. Recent evidences are difficult to reconcile with such an idea and suggest that the properties of muscle fibres that are likely to depend on myosin, such as velocity of shortening, can change without a change in myosin isoform. That a given myosin isoform can modify its properties without shifting to another isoform is confirmed by some analyses of isolated myosin in vitro. The present review is mainly focused on findings that challenge the role of myosin isoforms in determining the functional heterogeneity of skeletal muscle. The work also reports on potential mechanisms behind such changes in myosin function independent of a shift in myosin isoform: the coexistence of different myosin heavy chain (MHC) isoforms in the same fibre, the existence of as yet undetected MHC isoforms, myosin light chain isoforms, post-translational modifications of myosin, the role of other myofibrillar proteins, geometry of the sarcomere and the myosin concentration in single fibres.
    Publication Pflügers Archiv: European Journal of Physiology
    Date Oct 2001
    URL http://www.ncbi.nlm.nih.gov/pubmed/11692261

    Tags:

    • Animals
    • Humans
    • Muscle Fibers, Skeletal
    • Myosin Heavy Chains
    • Myosins
    • Protein Isoforms
    • Sarcomeres

    Attachments

    • Functional heterogeneity of mammalian single muscle fibres do myosin isoforms tell the whole story.pdf
    • PubMed Snapshot
    • SpringerLink - Journal Article
  • Human skeletal muscle fibres: molecular and functional diversity

    Author R. Bottinelli
    Author C. Reggiani
    Abstract Contractile and energetic properties of human skeletal muscle have been studied for many years in vivo in the body. It has been, however, difficult to identify the specific role of muscle fibres in modulating muscle performance. Recently it has become possible to dissect short segments of single human muscle fibres from biopsy samples and make them work in nearly physiologic conditions in vitro. At the same time, the development of molecular biology has provided a wealth of information on muscle proteins and their genes and new techniques have allowed analysis of the protein isoform composition of the same fibre segments used for functional studies. In this way the histological identification of three main human muscle fibre types (I, IIA and IIX, previously called IIB) has been followed by a precise description of molecular composition and functional and biochemical properties. It has become apparent that the expression of different protein isoforms and therefore the existence of distinct muscle fibre phenotypes is one of the main determinants of the muscle performance in vivo. The present review will first describe the mechanisms through which molecular diversity is generated and how fibre types can be identified on the basis of structural and functional characteristics. Then the molecular and functional diversity will be examined with regard to (1) the myofibrillar apparatus; (2) the sarcolemma and the sarcoplasmic reticulum; and (3) the metabolic systems devoted to producing ATP. The last section of the review will discuss the advantage that fibre diversity can offer in optimizing muscle contractile performance. Corresponding author. Tel.: +39-0382-507257; fax: +39-0382-507664; email: r.bottinelli@unipv.it
    Publication Progress in Biophysics and Molecular Biology
    Date May 2000
    URL http://www.sciencedirect.com/science?
    _ob=ArticleURL&…

    Attachments

    • Bottinelli-review MHC.pdf
    • ScienceDirect Snapshot
  • Muscle strength and its development. New perspectives

    Author R M Enoka
    Abstract Skeletal muscle undergoes substantial adaptation when it is subjected to a strength training regimen. At one extreme, these effects are manifested as profound morphological changes, such as those exemplified by bodybuilders. However, it is possible to increase strength without any change in muscle size. This dissociation underscores the notion that strength is not solely a property of muscle but rather it is a property of the motor system. The nervous system seems to be of paramount importance for the expression and development of strength. Indeed, it is probable that increases in strength can be achieved without morphological changes in muscle but not without neural adaptations. This review focuses on the role of the nervous system in the development of strength. In the strength literature, 3 topics exemplify the importance of the nervous system in strength development. These 3 topics are considered in detail in the review: electromyostimulation, cross-training effects, and EMG-force relationships. Evidence is presented from several different paradigms emphasising the significant contribution of neural mechanisms to the gains in strength with short term training. Although little is known about the specific neural mechanisms associated with strength training adaptations, the literature emphasises that the measure of human performance known as strength can be influenced by a variety of neurophysiological processes.
    Publication Sports Medicine (Auckland, N.Z.)
    Date Sep 1988
    URL http://www.ncbi.nlm.nih.gov/pubmed/3055145

    Tags:

    • Electric Stimulation
    • Electromyography
    • Humans
    • Isometric Contraction
    • Motor Endplate
    • Muscle Contraction
    • Muscles
    • Physical Education and Training

    Attachments

    • PubMed Snapshot
  • Nerve-Muscle Interaction

    Author Gerta Vrbova
    Contributor Te Gordon
    Contributor Rosem Jones
    Edition 2nd
    Place London
    Publisher Chapman & Hall
    Date 1995
    # of Pages 256

    Tags:

    • innervat
    • Muscles
    • Myoneural junct
    • Neuromuscular disea
    • Neuromuscular Junct
    • Neuromuscular transmiss
    • Neurophysiol

    Attachments

    • Nerve -Muscle Interaction chap.5 - bibliography.pdf
    • Nerve -Muscle Interaction chap.5 - Vrbova, Gordon, Jones - 1995.pdf
  • Neuromechanics of human movement

    Author Roger Enoka
    Abstract (from Amazon) Drawing on the disciplines of neurophysiology and physics, Neuromechanics of Human Movement, Fourth Edition, explores how the nervous system controls the actions of muscles to produce human motion in relation to biomechanical principles. This contemporary approach is much different from the traditional approach, which focuses solely on mechanics and does not consider the role of the sensory system in the control of human movement. Neuromechanics of Human Movement, Fourth Edition, provides a scientific foundation to the study of human movement, and as such it uses precise terms and definitions when discussing ideas and utilizing the international metric system (SI). Readers will find an appendix that helps in identifying the SI metric units as well as other learning tools, including a glossary of terms and two other appendixes that cover conversion factors and equations. Throughout the text, the content is visually reinforced with more than 750 illustrations, many of which are new or upgraded from the previous edition and include specific illustrations of the neuromechanics involved in sport and rehabilitation movements. Finally, the text contains more than 1,500 updated references and suggested reading lists for each chapter. To further enhance this fourth edition, significant content updates have been made to ensure the latest information is presented for both research and clinical environments: * New coverage regarding electromyography (EMG) that demonstrates the connection between the nervous system and the muscle by measuring the activation signal, allowing readers to better understand how motion is activated * Additional examples that underscore recent research developments in reaching and grasping activities for rehabilitation * In-depth coverage of the motor system that addresses excitable membranes, muscle and motor units, and voluntary movement * Expanded discussion of neuromuscular system adaptations to the aging process * Neuromuscular system adaptations with particular application to rehabilitation To encourage a comprehensive learning experience, this updated edition follows a logical progression where each part builds on the material from the previous section. It begins with an introduction to the biomechanical terms and concepts commonly used to describe movement, focusing on the relation between force and motion. Once readers have grasped the basic laws of motion, the text continues by considering the essential neurophysiological concepts that help to explain movement produced by the nervous system and muscle. The author uses a "bottom-up" approach for this explanation that begins with the principles of electricity and extends up to connections within the cerebral cortex. This approach encompasses the essentials of electricity responsible for the excitability of cell membranes and explains the relations between spinal neurons and muscle fibers. The third and final part of the text concludes by describing the ways in which the motor system adapts to various types of physical stress. These adapative capabilities include altering core temperature, phenomena such as strength and power training, adaptations that occur after periods of reduced activity, motor recovery from injury; and changes that occur with aging. Readers will understand how acute adjustments can be made to the motor system through interventions such as warm-up, flexibility, muscle soreness, and muscle fatigue. Author Roger M. Enoka, PhD, is a professor and chair in the department of integrative physiology at the University of Colorado at Boulder. He is also a professor in the Health Sciences Center, department of medicine, geriatrics, at the University of Colorado. Previously, Enoka was a biomechanist in the department of biomedical engineering at the Cleveland Clinic Foundation and a professor in the department of physiology at the University of Arizona. For more than 30 years, Enoka has focused his research and teaching on the combination of biomechanics and neurophysiology of movement. He conducts an interdisciplinary research program, which has received continuous funding by the National Institutes of Health for almost two decades. Internationally known for his achievements as a teacher and researcher, Enoka is the author of about 350 journal articles, books, chapters, reviews, and abstracts related to his research. He is also a reviewer for numerous journals and serves on the editorial board for the Journal of Applied Physiology, Journal of Electromyography and Kinesiology, Motor Control, Sports Medicine, Muscle and Nerve, and the Scandinavian Journal of Medicine and Science in Sports. Enoka&apos;s professional affiliations include the American College of Sports Medicine, the American Physiological Society, International Society of Biomechanics, and the Society for Neuroscience. He is a former member of the Advisory Panel on Research for the American Physical Therapy Association and the Respiratory and Applied Physiology Study Section of the National Institutes of Health. Enoka is also a past president and current member of the American Society of Biomechanics.
    Edition 4. ed.
    Place Champaign IL [u.a.]
    Publisher Human Kinetics
    Date 2008
  • Neuromuscular fatigue during a long-duration cycling exercise

    Author Romuald Lepers
    Author Nicola A Maffiuletti
    Author Ludovic Rochette
    Author Julien Brugniaux
    Author Guillaume Y Millet
    Abstract The effects of prolonged cycling on neuromuscular parameters were studied in nine endurance-trained subjects during a 5-h exercise sustained at 55% of the maximal aerobic power. Torque during maximal voluntary contraction (MVC) of the quadriceps muscle decreased progressively throughout the exercise (P < 0.01) and was 18% less at the end of exercise compared with the preexercise value. Peak twitch torque, contraction time, and total area of mechanical response decreased significantly (P < 0.05) after the first hour of exercise. In contrast, changes in M-wave characteristics were significant only after the fourth hour of the exercise. Significant reductions (P < 0.05) in electromyographic activity normalized to the M wave occurred after the first hour for the vastus lateralis muscle but only at the end of the exercise for the vastus medialis muscle. Muscle activation level, assessed by the twitch interpolation technique, decreased by 8% (P < 0.05) at the end of the exercise. The results suggest that the time course is such that the contractile properties are significantly altered after the first hour, whereas excitability and central drive are more impaired toward the latter stages of the 5-h cycling exercise.
    Publication Journal of Applied Physiology (Bethesda, Md.: 1985)
    Date Apr 2002
    URL http://www.ncbi.nlm.nih.gov/pubmed/11896014

    Tags:

    • Adult
    • Bicycling
    • Electromyography
    • Exercise
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Fatigue
    • Muscle, Skeletal
    • Physical Endurance
    • Thigh
    • Torque

    Attachments

    • PubMed Snapshot
  • Short vs. long rest period between the sets in hypertrophic resistance training: influence on muscle strength, size, and hormonal adaptations in trained men

    Author Juha P Ahtiainen
    Author Arto Pakarinen
    Author Markku Alen
    Author William J Kraemer
    Author Keijo Häkkinen
    Abstract Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magnetic resonance imaging (MRI) were measured at months 0, 3, and 6. The 2 hypertrophic training protocols used in training for the leg extensors (leg presses and squats with 10RM sets) were also examined in the laboratory conditions at months 0, 3, and 6. The exercise protocols were similar with regard to the total volume of work (loads x sets x reps), but differed with regard to the intensity and the length of rest between the sets (higher intensity and longer rest of 5 minutes vs. somewhat lower intensity but shorter rest of 2 minutes). Before and immediately after the protocols, maximal isometric force and electromyographic (EMG) activity of the leg extensors were measured and blood samples were drawn for determination of serum T, FT, C, and growth hormone (GH) concentrations and blood lactate. Both protocols before the experimental training period (month 0) led to large acute increases (p < 0.05-0.001) in serum T, FT, C , and GH concentrations, as well as to large acute decreases (p < 0.05-0.001) in maximal isometric force and EMG activity. However, no significant differences were observed between the protocols. Significant increases of 7% in maximal isometric force, 16% in the right leg 1RM, and 4% in the muscle CSA of the quadriceps femoris were observed during the 6-month strength-training period. However, both 3-month training periods performed with either the longer or the shorter rest periods between the sets resulted in similar gains in muscle mass and strength. No statistically significant changes were observed in basal hormone concentrations or in the profiles of acute hormonal responses during the entire 6-month experimental training period. The present study indicated that, within typical hypertrophic strength-training protocols used in the present study, the length of the recovery times between the sets (2 vs. 5 minutes) did not have an influence on the magnitude of acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass in previously strength-trained men.
    Publication Journal of Strength and Conditioning Research / National Strength & Conditioning Association
    Date Aug 2005
    URL http://www.ncbi.nlm.nih.gov/pubmed/16095405

    Tags:

    • Adult
    • Cross-Over Studies
    • Diet
    • Electromyography
    • Human Growth Hormone
    • Humans
    • Hydrocortisone
    • Isometric Contraction
    • Leg
    • Male
    • Muscle, Skeletal
    • Physical Education and Training
    • Rest
    • Testosterone

    Attachments

    • PubMed Snapshot
  • The effects of a prolonged running exercise on strength characteristics

    Author R Lepers
    Author M L Pousson
    Author N A Maffiuletti
    Author A Martin
    Author J Van Hoecke
    Abstract The aim of this study was to examine concentric, isometric, and eccentric strength reductions in the quadriceps muscle following a prolonged running exercise. Before and after a 2 h run (28.4+/-1.4 km) peak torque (PT) of the knee extensors at angular velocities of -120, -90, -60, 0, 60, 120, 180, 240 degrees x s(-1) using an isokinetic dynamometer, electromyographic (EMG) activity of the vastus lateralis (VL) and vastus medialis (VM) muscles and height of a counter movement jump were recorded in twelve well-trained triathletes. Counter movement jump performances decreased by 10% and PT values were all significantly lower (p < 0.01) at each angular velocity following the run. The torque loss was significantly (p < 0.01) greater under eccentric contractions (from 18 to 21%) than under concentric ones (from 11 to 14%). EMG activity (RMS) was lower in both VL and VM muscles after the 2 h run but no difference existed in RMS losses between concentric and eccentric contractions. The present results demonstrate that 1) a prolonged running exercise more greatly affects eccentric force production in the quadriceps muscle, and 2) this specificity seems to be due to an impairment of the muscular contractile mechanism rather than a modification to the neural input.
    Publication International Journal of Sports Medicine
    Date May 2000
    URL http://www.ncbi.nlm.nih.gov/pubmed/10853699

    Tags:

    • Adult
    • Biomechanics
    • Electromyography
    • Ergometry
    • Humans
    • Knee
    • Male
    • Movement
    • Muscle Contraction
    • Muscle, Skeletal
    • Physical Endurance
    • Running
    • Torque

    Attachments

    • PubMed Snapshot
  • The relative contribution to the plantar-flexor torque of the soleus motor units activated by the H reflex and M response in humans

    Author N A Maffiuletti
    Author A Martin
    Author J Van Hoecke
    Author M Schieppati
    Abstract This study proposes a method of quantifying the relative contribution to the plantar-flexor torque of soleus H and M responses evoked by tibial nerve stimulation. For ten subjects, the amplitude of the twitch produced by the H wave was plotted against the corresponding potential, for stimuli producing H without M (i.e. in the ascending portion of the H-recruitment curve). It was then assumed that the contribution of H to twitches produced by M plus H was similar for similar H waves on the curve-descending portion. Hence, the contribution of M was estimated, for the range of M waves including those accompanying H(max). The estimated mechanical contributions of H and M wave increase linearly with their potentials, the slope of the relationship being greater for H than M. The interpretation of this finding is discussed. A simple formula for assessing the contribution of the H wave to the twitch torque is given.
    Publication Neuroscience Letters
    Date Jul 14, 2000
    URL http://www.ncbi.nlm.nih.gov/pubmed/10876077

    Tags:

    • Action Potentials
    • Adult
    • Electric Stimulation
    • Electromyography
    • H-Reflex
    • Humans
    • Male
    • Muscle Contraction
    • Muscle Fibers, Fast-Twitch
    • Muscle Fibers, Slow-Twitch
    • Muscle, Skeletal
    • Tibial Nerve
    • Torque

    Attachments

    • PubMed Snapshot


  • Back to Top

    Soft Tissue Repair

    • A review of the biophysical basis for the clinical application of electric fields in soft-tissue repair

      Author R C Lee
      Author D J Canaday
      Author H Doong
      Abstract Interest in the role of electrical interactions as epigenetic regulators of wound healing had its beginnings nearly 40 years ago. Because the mechanisms of action are not understood (which obviates rational therapy), the empiric application of fields to wounds has produced mixed results. However, taken collectively, clinical trials have demonstrated some beneficial effects. Tests on soft tissues of animals have shown that electric stimulation can influence the rate of wound healing and scar strength. Natural epithelial-derived sodium currents have been discovered in the wounds of invertebrates and mammals. It is theorized that these currents may be a normal controlling factor in wound healing. Therefore, perturbation of these signals is important to understand. The purpose of this review is to put into proper perspective the biophysical, physiological, and clinical data pertaining to use of electricity to control wound healing, with the goal of minimizing much of the prevailing confusion.
      Publication The Journal of Burn Care & Rehabilitation
      Date 1993 May-Jun
      URL http://www.ncbi.nlm.nih.gov/pubmed/8360237

      Tags:

      • Animals
      • Electric Stimulation Therapy
      • Electrophysiology
      • Humans
      • Skin
      • Tendon Injuries
      • Wound Healing

      Attachments

      • A Review of the Biophysical Basis for the Clinical Application of Electric Fields in Soft-Tissue repair.pdf
    • Control of calcium entry in human fibroblasts by frequency-dependent electrical stimulation

      Author Michael R Cho
      Author Joan P Marler
      Author Hemant S Thatte
      Author David E Golan
      Abstract Modulation of intracellular calcium ion concentration ((Ca2+)i) could be used to control cellular and molecular responses that are important in cell and tissue engineering. Electrical stimulation (ES) has been used to activate plasma membrane ion channels including Ca2+channels, and to induce changes in (Ca2+)i. Strong direct current (dc) ES depolarizes the membrane electrical potential (MEP) and, thereby, causes rapid increases in (Ca2+)i. Electrocoupling mechanisms that could control (Ca2+)i increases induced by modes of ES other than dc have not been elucidated, however. Here we report that 30 min of continuous exposure to a 1 or 10 Hz, 2 V/cm ES induces an (Ca2+)i increase by approximately 6-fold (baseline 25 nM) in human fibroblasts in culture. In contrast, a 100 Hz, 2 V/cm ES causes no significant (Ca2+)i increase. Either depletion of Ca2+from the extracellular medium or incubation of cells with verapamil inhibits the (Ca2+)i increase, indicating that Ca2+ influx through verapamil-sensitive Ca2+channels is required for the (Ca2+)i increase induced by oscillatory ES. More intense ES by a 1 Hz or a dc 10 V/cm electric field causes a rapid 20 to 25-fold (Ca2+)i increase. We hypothesize that selective, partial activation of Ca2+channels is likely to mediate Ca2+influx. These results suggest that optimal ES could be used to control Ca2+entry and, thereby, regulate cellular calcium homeostasis without adversely affecting cell viability.
      Publication Frontiers in Bioscience: A Journal and Virtual Library
      Date Jan 1, 2002
      URL http://www.ncbi.nlm.nih.gov/pubmed/11779692

      Tags:

      • Calcium
      • Calcium Channels
      • Cations
      • Cell Line
      • Electric Stimulation
      • Extracellular Space
      • Fibroblasts
      • Fluorescent Dyes
      • Humans
      • Microscopy, Fluorescence
      • Time Factors
    • DNA synthesis in cartilage cells is stimulated by oscillating electric fields

      Author G A Rodan
      Author L A Bourret
      Author L A Norton
      Abstract External oscillating electric fields (1166 volts per centimeter, 5 hertz) enhanced the incorporation of [3H] thymidine into the DNA of chondrocytes isolated from the proliferative layer of embryonic (16 days) chick epiphysis. Verapamil or tetrodotoxin at 10(-6)M concentrations completely blocked the electric field effect. Tetracaine reduced the incorporation of [3H] thymidine in both control and electrically stimulated cells. The findings support the hypothesis that Na and Ca2 fluxes generated by the electrical perturbation trigger DNA synthesis in these cells.
      Publication Science (New York, N.Y.)
      Date Feb 10, 1978
      URL http://www.ncbi.nlm.nih.gov/pubmed/625660

      Tags:

      • Animals
      • Calcium
      • Cartilage
      • Chick Embryo
      • DNA
      • Electric Stimulation
      • Electricity
      • Membrane Potentials
      • Skin
      • Sodium
      • Tetrodotoxin
      • Verapamil
    • Effect of electrical stimulation on chronic wound healing: a meta-analysis

      Author S E Gardner
      Author R A Frantz
      Author F L Schmidt
      Abstract The purpose of this meta-analysis was to quantify the effect of electrical stimulation on chronic wound healing. Fifteen studies, which included 24 electrical stimulation samples and 15 control samples, were analyzed. The average rate of healing per week was calculated for the electrical stimulation and control samples. Ninety-five percentage confidence intervals were also calculated. The samples were then grouped by type of electrical stimulation device and chronic wound and reanalyzed. Rate of healing per week was 22% for electrical stimulation samples and 9% for control samples. The net effect of electrical stimulation was 13% per week, an increase of 144% over the control rate. The 95% confidence intervals of the electrical stimulation (18-26%) and control samples (3.8-14%) did not overlap. Electrical stimulation was most effective on pressure ulcers (net effect = 13%). Findings regarding the relative effectiveness of different types of electrical stimulation device were inconclusive. Although electrical stimulation produces a substantial improvement in the healing of chronic wounds, further research is needed to identify which electrical stimulation devices are most effective and which wounds respond best to this treatment.
      Publication Wound Repair and Regeneration: Official Publication of the Wound Healing Society [and] the European Tissue Repair Society
      Date 1999 Nov-Dec
      URL http://www.ncbi.nlm.nih.gov/pubmed/10633009

      Tags:

      • Electric Stimulation Therapy
      • Humans
      • Leg Ulcer
      • Pressure Ulcer
      • Wound Healing

      Attachments

      • Effect of Electrical Stimulation on chronic wound healing - a meta analysis.pdf
    • Electric stimulation of human fibroblasts causes an increase in Ca2+ influx and the exposure of additional insulin receptors

      Author G J Bourguignon
      Author W Jy
      Author L Y Bourguignon
      Abstract Previously we reported that treating human fibroblasts in cell culture with high-voltage, pulsed galvanic stimulation (HVPGS) can significantly increase cellular protein and DNA synthesis (Bourguignon and Bourguignon: FASEB J., 1:398-402, 1987). In this study we have identified two of the early cellular events which occur following exposure to HVPGS: 1) an increase in Ca2+ uptake from the external medium and 2) an increase in the number of insulin receptors on the fibroblast cell surface. The increase in Ca2+ uptake begins within the first minute of electric stimulation while increased insulin binding is not detected until the second minute of stimulation. The HVPGS-induced increase in insulin binding can be inhibited by bepridil, a specific Ca2+ channel blocker, suggesting that the Ca2+ influx is required for the exposure of additional insulin receptors on the cell surface. Furthermore, we have determined that the addition of insulin to electrically stimulated cultures results in 1) an immediate, second increase in Ca2+ uptake and 2) significant increases in both protein and DNA synthesis compared to cells which were not stimulated. All three of these insulin-dependent effects are also inhibited by bepridil. Based on these results, we propose that HVPGS initially triggers the opening of voltage-sensitive calcium channels in the fibroblast plasma membrane. The increased level of intracellular Ca2+ then induces the exposure of additional insulin receptors, the fibroblasts will significantly increase both protein and DNA synthesis.
      Publication Journal of Cellular Physiology
      Date Aug 1989
      URL http://www.ncbi.nlm.nih.gov/pubmed/2663886

      Tags:

      • Blood Proteins
      • Calcium
      • Cell Membrane
      • DNA
      • Electric Stimulation
      • Fibroblasts
      • Humans
      • Insulin
      • Receptor Aggregation
      • Receptor, Insulin

      Attachments

      • Electric Stimulation of Human Fibroblasts Causes an Increase in Ca2+ Influx and the Exposure of Additional Insulin Receptors.pdf
    • Electric stimulation of protein and DNA synthesis in human fibroblasts

      Author G J Bourguignon
      Author L Y Bourguignon
      Abstract Human fibroblast cell cultures were employed as a model system to rapidly examine several potentially important variables involved in the use of high-voltage, pulsed galvanic stimulation (HVPGS) to increase the healing rate of soft tissue injuries. Fibroblasts were grown on Millipore filters and exposed to HVPGS of various voltages and pulse rates for 20 min in a rectangular, plastic chamber filled with growth medium. Filters with attached cells were placed either in the center of the chamber or close to the positive or negative electrode. Protein synthesis and DNA synthesis were monitored after stimulation using the radioactively labeled precursors, [3H]proline and [3H]thymidine, respectively. The major results obtained in this study are as follows: 1) the rates of both protein and DNA synthesis can be significantly increased by specific combinations of HVPGS voltage and pulse rate; 2) maximum stimulation of protein and DNA synthesis was obtained at 50 and 75 V, respectively, with a pulse rate of 100 pulses/s and the cells located near the negative electrode; and 3) exposure to HVPGS intensities greater than 250 V (at all pulse rates and locations within the chamber) is inhibitory for both protein and DNA synthesis. In view of the results obtained in preliminary clinical studies on the use of HVPGS for the treatment of dermal ulcers, it appears that similar voltages, pulse rates, and relative electrode location may be required for maximum acceleration of human skin wound healing.
      Publication The FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
      Date Nov 1987
      URL http://www.ncbi.nlm.nih.gov/pubmed/3678699

      Tags:

      • DNA
      • Electric Stimulation
      • Electrodes
      • Fibroblasts
      • Humans
      • Kinetics
      • Protein Biosynthesis
      • Wound Healing

      Attachments

      • 398.full.pdf (application/pdf Object)
      • 398.full[1].pdf
    • Plasma medicine: an introductory review

      Author G. Kroesen
      Author G. Morfill
      Author T. Nosenko
      Author T. Shimizu
      Author J. Van Dijk
      Author J L Zimmermann
      Author M G Kong
      Publication New Journal of Physics

      Attachments

      • Plasma medicine - an introductory review.pdf
    • Reorganization of microfilament structure induced by ac electric fields

      Author M R Cho
      Author H S Thatte
      Author R C Lee
      Author D E Golan
      Abstract AC electric fields induce redistribution of integral membrane proteins. Cell-surface receptor redistribution does not consistently follow electric field lines and depends critically on the frequency of the applied ac electric fields, suggesting that mechanisms other than electroosmosis are involved. We hypothesized that cytoskeletal reorganization is responsible for electric field-induced cell-surface receptor redistribution, and used fluorescence video microscopy to study the reorganization of microfilaments in human hepatoma (Hep3B) cells exposed to low-frequency electric fields ranging in strength from 25 mV/cm to 20 V/cm (peak to peak). The frequency of the applied electric field was varied from 1 to 120 Hz and the field exposure duration from 1 to 60 min. In control cells, cytoplasmic microfilaments were aligned in the form of continuous parallel cables along the longitudinal axis of the cell. Exposure of cells to ac electric fields induced alterations in microfilament structure in a manner that depended on the frequency of the applied field. A 1 or 10 Hz ac field caused microfilament reorganization from continuous, aligned cable structures to discontinuous globular patches. In contrast, the structure of microfilaments in cells exposed to 20-120 Hz electric fields did not differ from that in control cells. The extent of microfilament reorganization increased nonlinearly with the electric field strength. The characteristic time for microfilament reorganization in cells exposed to a 1 Hz, 20 V/cm electric field was approximately 5 min. Applied ac electric fields could initiate signal transduction cascades, which in turn cause reorganization of cytoskeletal structures.
      Publication The FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
      Date Nov 1996
      URL http://www.ncbi.nlm.nih.gov/pubmed/8940302

      Tags:

      • Cell Survival
      • Electricity
      • Humans
      • Microfilaments
      • Microscopy, Fluorescence
      • Microscopy, Video
      • Tumor Cells, Cultured

      Attachments

      • Reorganization of microfilament structure induced by AC electric fields.pdf
    • Wound healing: an overview

      Author George, 2nd Broughton
      Author Jeffrey E Janis
      Author Christopher E Attinger
      Abstract Understanding wound healing today involves much more than simply stating that there are three phases: inflammation, proliferation, and maturation. Wound healing is a complex series of reactions and interactions among cells and "mediators." Each year, new mediators are discovered and our understanding of inflammatory mediators and cellular interactions grows. This article will attempt to provide a concise overview on wound healing and wound management.
      Publication Plastic and Reconstructive Surgery
      Date Jun 2006
      URL http://www.ncbi.nlm.nih.gov/pubmed/16801750

      Tags:

      • Cell Division
      • Cicatrix
      • Humans
      • Inflammation
      • Wound Healing
      • Wounds and Injuries

      Attachments

      • Wound Healing - An Overview.pdf