0000000000116193
AUTHOR
Julien Gondin
Plantar Flexion Torque as a Function of Time of Day
The possible peripheral and/or central origin in the mechanisms responsible for day-time fluctuation in maximal torque of the triceps surae muscle were investigated with a special emphasis on antagonist muscle coactivation. Eleven healthy male subjects (physical education students) took part in this investigation. The electromechanical properties of the plantar flexor muscles were recorded at two different times of day: between 06:00 h and 08:00 h in the morning and between 17:00 h and 19:00 h in the evening. To investigate peripheral mechanisms, the posterior tibial nerve was stimulated at rest, using percutaneous electrical stimuli, to evoke single twitch, double twitch, and maximal tetan…
Neuromuscular electrical stimulation training induces atypical adaptations of the human skeletal muscle phenotype: a functional and proteomic analysis
Import JabRef | WosArea Physiology; Sport Sciences; International audience; The aim of the present study was to define the chronic effects of neuromuscular electrical stimulation (NMES) on the neuromuscular properties of human skeletal muscle. Eight young healthy male subjects were subjected to 25 sessions of isometric NMES of the quadriceps muscle over an 8-wk period. Needle biopsies were taken from the vastus lateralis muscle before and after training. The training status, myosin heavy chain (MHC) isoform distribution, and global protein pattern, as assessed by proteomic analysis, widely varied among subjects at baseline and prompted the identification of two subgroups: an "active" (ACT) …
Electromyostimulation Training Effects on Neural Drive and Muscle Architecture
GONDIN, J., M., GUETTE, Y. BALLAY, and A. MARTIN. Electromyostimulation Training Effects on Neural Drive and Muscle Architecture. Med. Sci. Sports Exerc., Vol. 37, No. 8, pp. 1291–1299, 2005. Purpose: The purpose of the study was to investigate the effect of 4 and 8 wk of electromyostimulation (EMS) training on both muscular and neural adaptations of the knee extensor muscles. Methods: Twenty males were divided into the electrostimulated group (EG, N 12) and the control group (CG, N 8). The training program consisted of 32 sessions of isometric EMS over an 8-wk period. All subjects were tested at baseline (B) and retested after 4 (WK4) and 8 (WK8) wk of EMS training. The EMG activity and mu…
Time‐of‐Day Effect on the Torque and Neuromuscular Properties of Dominant and Non‐Dominant Quadriceps Femoris
The study was conducted first, to determine the possibility of a dichotomy between circadian rhythm of maximal torque production of the knee extensors of the dominant and non-dominant legs, and second, to determine whether the possible dichotomy could be linked to a change in the downward drive of the central nervous system and/or to phenomena prevailing at the muscular level. The dominant leg was defined as the one with which subjects spontaneously kick a football. Tests were performed at 06:00, 10:00, 14:00, 18:00, and 22:00 h. To distinguish the neural and muscular mechanisms that influence muscle strength, the electromyographic and mechanical muscle responses associated with electricall…
Effects of Neuromuscular Electrical Stimulation Training on Endurance Performance
Various electrical stimulation modalities are used as adjuvants to conventional training and rehabilitation programs to increase bodily function or to reduce symptoms, such as pain. One of these modalities, neuromuscular electrical stimulation (NMES), commonly refers to the transcutaneous application of electrical currents to a target muscle group with the objective to depolarize motor neurons and consequently elicit skeletal muscle contractions of substantial intensity (usually ranging from 10 to 60% of the maximal voluntary contraction). Because NMES can generate considerable muscle tension, it is frequently used as a strength training technique for healthy adults and athletes, but also a…
The Etiology of Muscle Fatigue Differs between Two Electrical Stimulation Protocols
International audience; Purpose: This study aimed at investigating the mechanisms involved in the force reduction induced by two electrical stimulation (ES) protocols that were designed to activate motor units differently. Methods: The triceps surae of 11 healthy subjects (8 men; age, similar to 28 yr) was activated using ES applied over the tibial nerve. Two ES protocols (conventional [CONV]: 20 Hz, 0.05 ms vs wide-pulse high-frequency [WPHF]: 80 Hz, 1 ms) were performed and involved 40 trains (6 s on-6 s off) delivered at an intensity (I-ES) evoking 20% of maximal voluntary contraction. To analyze the mechanical properties of the motor units activated at I-ES, force-frequency relation was…
Effect of electrostimulation training-detraining on neuromuscular fatigue mechanisms.
The aim of this study was to evaluate the effects of neuromuscular electrical stimulation (NMES) training and subsequent detraining on neuromuscular fatigue mechanisms. Ten young healthy men completed one NMES fatigue protocol before and after a NMES training program of 4 weeks and again after 4 weeks of detraining. Muscle fatigue (maximal voluntary torque loss), central fatigue (activation failure), and peripheral fatigue (transmission failure and contractile failure) of the plantar flexor muscles were assessed by using a series of electrically evoked and voluntary contractions with concomitant electromyographic and torque recordings. At baseline, maximal voluntary torque decreased signifi…
Twitch interpolation during equal-intensity voluntary and electrically-evoked isometric contractions of the quadriceps muscle
It has been suggested that, during contractions triggered by electrical stimulation, motor units are recruited in a reversed sequence compared to voluntary contraction. The classic view is that lar...
Central and Peripheral Contributions to Fatigue after Electrostimulation Training
Purpose: We examined the effect of 4 (WK4) and 8 wk (WK8) of neuromuscular electrical stimulation (NMES) training on both endurance time and mechanisms contributing to task failure. Methods: Ten males performed a fatiguing isometric contraction with the knee extensor muscles at 20% of maximal voluntary contraction (MVC) until exhaustion before (B), at WK4, and at WK8 of NMES training. The electromyographic (EMG) activity and muscle activation obtained under MVC were recorded before and after the fatiguing task to assess central fatigue. Torque and EMG responses obtained under electrically evoked contractions were examined before and after the fatiguing task to analyze peripheral fatigue. Re…
Neural drive preservation after detraining following neuromuscular electrical stimulation training
The purpose of the study was to investigate the behaviour of the central nervous system when 5 weeks of neuromuscular electrical stimulation (NMES) training was followed by 5 weeks of detraining. Nineteen males were divided into the neuromuscular electrostimulated group (EG, n=12) and the control group (CG, n=7). The training program consisted of 15 sessions of isometric NMES over a 5-week period. The EG subjects were tested before training (PRE), after 5 weeks of NMES training (POST) and after 5 weeks of detraining (DE) while CG subjects were only tested at PRE and at POST. Soleus (SOL) and gastrocnemii (GAS) maximal H-reflex and M-wave potentials were evoked at rest (i.e., H(max) and M(ma…