Soleus- and Gastrocnemii-Evoked V-Wave Responses Increase After Neuromuscular Electrical Stimulation Training

2006 ◽  
Vol 95 (6) ◽  
pp. 3328-3335 ◽  
Author(s):  
Julien Gondin ◽  
Julien Duclay ◽  
Alain Martin

The aim of the study was to use combined longitudinal measurements of soleus (SOL) and gastrocnemii evoked V-wave and H-reflex responses to determine the site of adaptations within the central nervous system induced by 5 wk of neuromuscular electrical stimulation (NMES) training of the plantar flexor muscles. Nineteen healthy males subjects were divided into a neuromuscular electrostimulated group ( n = 12) and a control group ( n = 7). The training program consisted of 15 sessions of isometric NMES over a 5-wk period. All subjects were tested before and after the 5-wk period. SOL, lateral gastrocnemius (LG), and medial gastrocnemius (MG) maximal H-reflex and M-wave potentials were evoked at rest (i.e., Hmax and Mmax, respectively) and during maximal voluntary contraction (MVC) (i.e., Hsup and Msup, respectively). During MVC, a supramaximal stimulus was delivered that allowed us to record the V-wave peak-to-peak amplitudes from all three muscles. The SOL, LG, and MG electromyographic (EMG) activity as well as muscle activation (twitch interpolation technique) were also quantified during MVC. After training, plantar flexor MVC increased significantly by 22% ( P < 0.001). Torque gains were accompanied by an increase in muscle activation (+11%, P < 0.05), SOL, LG, and MG normalized EMG activity (+51, +54, and +60%, respectively, P < 0.05) and V/Msup ratios (+81, +76, and +97%, respectively, P < 0.05). Hmax/Mmax and Hsup/Msup ratios for all three muscles were unchanged after training. In conclusion, the increase in voluntary torque after 5 wk of NMES training could be ascribed to an increased volitional drive from the supraspinal centers and/or adaptations occurring at the spinal level.

2014 ◽  
Vol 117 (12) ◽  
pp. 1440-1450 ◽  
Author(s):  
Julien Duclay ◽  
Benjamin Pasquet ◽  
Alain Martin ◽  
Jacques Duchateau

This study investigated the influence of the torque produced by plantar flexor muscles on cortical and spinal excitability during lengthening and shortening voluntary contractions. To that purpose, modulations of motor-evoked potential (MEP) and Hoffmann (H) reflex were compared in the soleus (SOL) and medial gastrocnemius (MG) during anisometric submaximal and maximal voluntary contraction (MVC) of the plantar flexor muscles. For the submaximal shortening and lengthening contractions, the target torque was set at 50% of their respective MVC force. The results indicate that the amplitudes of both MEP and H-reflex responses, normalized to the maximal M wave, were significantly ( P < 0.05) lower during lengthening compared with shortening submaximal contraction. For these two parameters, the reduction reached, respectively, 22.1 and 31.9% for the SOL and 34.5 and 29.3% for the MG. During MVC, normalized MEP and H reflex of the SOL were both reduced significantly by 19.9% ( P < 0.05) and 29.9% ( P < 0.001) during lengthening and shortening contraction, respectively, whereas no significant change ( P > 0.05) was observed for MG. In addition, the silent period in the ongoing electromyogram (EMG) activity following the MEP was significantly ( P < 0.01) briefer during lengthening than shortening contractions but did not differ ( P > 0.05) between contraction intensities and muscles. Together, these results indicate that cortical and spinal mechanisms involved in the modulation of muscle activation during shortening and lengthening contractions differ between synergistic muscles according to the torque produced. Data further document previous studies reporting that the specific modulation of muscle activation during lengthening contraction is not torque dependent.


Author(s):  
Amandine Bouguetoch ◽  
Alain Martin ◽  
Sidney Grosprêtre

Abstract Introduction Training stimuli that partially activate the neuromuscular system, such as motor imagery (MI) or neuromuscular electrical stimulation (NMES), have been previously shown as efficient tools to induce strength gains. Here the efficacy of MI, NMES or NMES + MI trainings has been compared. Methods Thirty-seven participants were enrolled in a training program of ten sessions in 2 weeks targeting plantar flexor muscles, distributed in four groups: MI, NMES, NMES + MI and control. Each group underwent forty contractions in each session, NMES + MI group doing 20 contractions of each modality. Before and after, the neuromuscular function was tested through the recording of maximal voluntary contraction (MVC), but also electrophysiological and mechanical responses associated with electrical nerve stimulation. Muscle architecture was assessed by ultrasonography. Results MVC increased by 11.3 ± 3.5% in NMES group, by 13.8 ± 5.6% in MI, while unchanged for NMES + MI and control. During MVC, a significant increase in V-wave without associated changes in superimposed H-reflex has been observed for NMES and MI, suggesting that neural adaptations occurred at supraspinal level. Rest spinal excitability was increased in the MI group while decreased in the NMES group. No change in muscle architecture (pennation angle, fascicle length) has been found in any group but muscular peak twitch and soleus maximal M-wave increased in the NMES group only. Conclusion Finally, MI and NMES seem to be efficient stimuli to improve strength, although both exhibited different and specific neural plasticity. On its side, NMES + MI combination did not provide the expected gains, suggesting that their effects are not simply cumulative, or even are competitive.


2018 ◽  
Vol 33 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Marwa Mekki ◽  
Thierry Paillard ◽  
Sonia Sahli ◽  
Zouhair Tabka ◽  
Yassine Trabelsi

Objective: To investigate the effectiveness of neuromuscular electrical stimulation added to pulmonary rehabilitation on walking tolerance and balance in patients with chronic obstructive pulmonary disease (COPD). Design: Randomized clinical trial. Setting: Outpatient, Faculty of Medicine of Sousse, Tunisia. Subjects: A total of 45 patients with COPD were assigned to an intervention group ( n = 25) or a control group ( n = 20). Interventions: The intervention group underwent a neuromuscular electrical stimulation added to pulmonary rehabilitation, and the control group underwent only a pulmonary rehabilitation, three times per week during six months. Main Measures: Measures were taken at baseline and after six months of training. A stabilometric platform, time up and go, Berg balance scale tests, 6 minute walking test, and the maximal voluntary contraction were measured. Results: In the intervention group, an increase in an exercise tolerance manifested by a longer distance walked in 6 minute walking test 619.5 (39.6) m was observed in comparison to the control group 576.3 (31.5) m. The values of the time up and go, Berg balance scale, and maximal voluntary contraction in the intervention group at follow-up were significantly higher than those in the control group ( P  = 0.02, P  = 0.01, P  = 0.0002, respectively). The center of pressure in the mediolateral and in the anteroposterior directions, as well as the center of pressure area was significantly more improved in open eyes and closed eyes in the intervention group compared to the control group ( P < 0.001). Conclusion: The neuromuscular electrical stimulation added to pulmonary rehabilitation group benefited from better walking tolerance and greater balance improvement than the only pulmonary rehabilitation.


2007 ◽  
Vol 103 (1) ◽  
pp. 402-411 ◽  
Author(s):  
Christopher Del Balso ◽  
E. Cafarelli

This study employed longitudinal measures of evoked spinal reflex responses (Hoffman reflex, V wave) to investigate changes in the activation of muscle and to determine if there are “linked” neural adaptations in the motor pathway following isometric resistance training. Twenty healthy, sedentary males were randomly assigned to either the trained ( n = 10) or control group ( n = 10). The training protocol consisted of 12 sessions of isometric resistance training of the plantar flexor muscles over a 4-wk period. All subjects were tested prior to and after the 4-wk period. To estimate changes in spinal excitability, soleus Hoffman (H) reflex and M wave recruitment curves were produced at rest and during submaximal contractions. Recruitment curves were analyzed using the slope method (Hslp/Mslp). Modulation of efferent neural drive was assessed through evoked V wave responses (V/Mmax) at 50, 75, and 100% maximal voluntary contraction (MVC). After 4 weeks, MVC torque increased 20.0 ± 13.9% (mean ± SD) in the trained group. The increase in MVC was accompanied by significant increases in the rate of torque development (42.5 ± 13.3%), the soleus surface electromyogram (60.7 ± 30.8%), voluntary activation (2.8 ± 0.1%), and the rate of activation (48.7 ± 24.3%). Hslp/Mslp was not altered by training; however, V/Mmax increased 57.3 ± 34.2% during MVC. These results suggest that increases in MVC observed in the first few days of isometric resistance training can be accounted for by an increase in the rate of activation at the onset of muscle contraction. Augmentation of muscle activation may be due to increased volitional drive from supraspinal centers.


Author(s):  
Ricardo N. O. Mesquita ◽  
Janet L. Taylor ◽  
Benjamin Kirk ◽  
Anthony J. Blazevich

Abstract Purpose Simultaneous application of tendon vibration and neuromuscular electrical stimulation (NMES) induces an involuntary sustained torque. We examined the effect of different NMES parameters (intensity, pattern of stimulation and pulse width) on the magnitude of the evoked involuntary torque. Methods Plantar flexor torque was recorded during 33-s Achilles tendon vibration with simultaneous 20-Hz NMES bouts on triceps surae (n = 20; 13 women). Intensity was set to elicit 10, 20 or 30% of maximal voluntary contraction torque (MVC), pulse width was narrow (0.2 ms) or wide (1 ms), and the stimulus pattern varied (5 × 2-s or 10 × 1-s). Up to 12 different trials were performed in a randomized order, and then repeated in those who produced a sustained involuntary torque after the cessation of vibration. Results Six of 7 men and 5 of 13 women produced a post-vibration sustained torque. Eight of 20 participants did not complete the 30% trials, as they were perceived as painful. Torque during vibration at the end of NMES and the increase in torque throughout the trial were significantly higher in 20 than 10% trials (n = 11; 9.7 ± 9.0 vs 7.1 ± 6.1% MVC and 4.3 ± 4.5 vs 3.6 ± 3.5% MVC, respectively). Post-vibration sustained torque was higher in wide pulse-width trials (5.4 ± 5.9 vs 4.1 ± 4.3% MVC). Measures of involuntary torque were not different between 20 and 30% trials (n = 8). Conclusion Bouts of 5 × 2-s NMES with wide pulse width eliciting 20% MVC provides the most robust responses and could be used to maximise the production of involuntary torque in triceps surae.


2004 ◽  
Vol 96 (4) ◽  
pp. 1516-1521 ◽  
Author(s):  
M. Klass ◽  
N. Guissard ◽  
J. Duchateau

The influence of repetitive dynamic fatiguing contractions on the neuromuscular characteristics of the human triceps surae was investigated in 10 subjects. The load was 50% of the torque produced during a maximal voluntary contraction, and the exercise ended when the ankle range of motion declined to 50% of control. The maximal torque of the triceps surae and the electromyographic (EMG) activities of the soleus and medial gastrocnemius were studied in response to voluntary and electrically induced contractions before and after the fatiguing task and after 5 min of recovery. Reflex activities were also tested by recording the Hoffmann reflex (H reflex) and tendon reflex (T reflex) in the soleus muscle. The results indicated that whereas the maximal voluntary contraction torque, tested in isometric conditions, was reduced to a greater extent ( P < 0.05) at 20° of plantar flexion (-33%) compared with the neutral position (-23%) of the ankle joint, the EMG activity of both muscles was not significantly reduced after fatigue. Muscle activation, tested by the interpolated-twitch method or the ratio of the voluntary EMG to the amplitude of the muscle action potential (M-wave), as well as the neuromuscular transmission and sarcolemmal excitation, tested by the M-wave amplitude, did not change significantly after the fatiguing exercise. Although the H and T reflexes declined slightly (10-13%; P < 0.05) after fatigue, these adjustments did not appear to have a direct deleterious effect on muscle activation. In contrast, alterations in the mechanical twitch time course and postactivation potentiation indicated that intracellular Ca2+-controlled excitation-contraction coupling processes most likely played a major role in the force decrease after dynamic fatiguing contractions performed for short duration.


2008 ◽  
Vol 105 (2) ◽  
pp. 463-472 ◽  
Author(s):  
Sandra K. Hunter ◽  
Tejin Yoon ◽  
Joseph Farinella ◽  
Erin E. Griffith ◽  
Alexander V. Ng

The purpose was to compare the time to failure and muscle activation patterns for a sustained isometric submaximal contraction with the dorsiflexor muscles when the foot was restrained to a force transducer (force task) compared with supporting an equivalent inertial load and unrestrained (position task). Fifteen men and women (mean ± SD; 21.1 ± 1.4 yr) performed the force and position tasks at 20% maximal voluntary contraction force until task failure. Maximal voluntary contraction force performed before the force and position tasks was similar (333 ± 71 vs. 334 ± 65 N), but the time to task failure was briefer for the position task (10.0 ± 6.2 vs. 21.3 ± 17.8 min, P < 0.05). The rate of increase in agonist root-mean-square electromyogram (EMG), EMG bursting activity, rating of perceived exertion, fluctuations in motor output, mean arterial pressure, and heart rate during the fatiguing contraction was greater for the position task. EMG activity of the vastus lateralis (lower leg stabilizer) and medial gastrocnemius (antagonist) increased more rapidly during the position task, but coactivation ratios (agonist vs. antagonist) were similar during the two tasks. Thus the difference in time to failure for the two tasks with the dorsiflexor muscles involved a greater level of neural activity and rate of motor unit recruitment during the position task, but did not involve a difference in coactivation. These findings have implications for rehabilitation and ergonomics in minimizing fatigue during prolonged activation of the dorsiflexor muscles.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dorian Glories ◽  
Mathias Soulhol ◽  
David Amarantini ◽  
Julien Duclay

AbstractDuring voluntary contractions, corticomuscular coherence (CMC) is thought to reflect a mutual interaction between cortical and muscle oscillatory activities, respectively measured by electroencephalography (EEG) and electromyography (EMG). However, it remains unclear whether CMC modulation would depend on the contribution of neural mechanisms acting at the spinal level. To this purpose, modulations of CMC were compared during submaximal isometric, shortening and lengthening contractions of the soleus (SOL) and the medial gastrocnemius (MG) with a concurrent analysis of changes in spinal excitability that may be reduced during lengthening contractions. Submaximal contractions intensity was set at 50% of the maximal SOL EMG activity. CMC was computed in the time–frequency domain between the Cz EEG electrode signal and the unrectified SOL or MG EMG signal. Spinal excitability was quantified through normalized Hoffmann (H) reflex amplitude. The results indicate that beta-band CMC and normalized H-reflex were significantly lower in SOL during lengthening compared with isometric contractions, but were similar in MG for all three muscle contraction types. Collectively, these results highlight an effect of contraction type on beta-band CMC, although it may differ between agonist synergist muscles. These novel findings also provide new evidence that beta-band CMC modulation may involve spinal regulatory mechanisms.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Raphael Uwamahoro ◽  
Kenneth Sundaraj ◽  
Indra Devi Subramaniam

AbstractThis research has proved that mechanomyographic (MMG) signals can be used for evaluating muscle performance. Stimulation of the lost physiological functions of a muscle using an electrical signal has been determined crucial in clinical and experimental settings in which voluntary contraction fails in stimulating specific muscles. Previous studies have already indicated that characterizing contractile properties of muscles using MMG through neuromuscular electrical stimulation (NMES) showed excellent reliability. Thus, this review highlights the use of MMG signals on evaluating skeletal muscles under electrical stimulation. In total, 336 original articles were identified from the Scopus and SpringerLink electronic databases using search keywords for studies published between 2000 and 2020, and their eligibility for inclusion in this review has been screened using various inclusion criteria. After screening, 62 studies remained for analysis, with two additional articles from the bibliography, were categorized into the following: (1) fatigue, (2) torque, (3) force, (4) stiffness, (5) electrode development, (6) reliability of MMG and NMES approaches, and (7) validation of these techniques in clinical monitoring. This review has found that MMG through NMES provides feature factors for muscle activity assessment, highlighting standardized electromyostimulation and MMG parameters from different experimental protocols. Despite the evidence of mathematical computations in quantifying MMG along with NMES, the requirement of the processing speed, and fluctuation of MMG signals influence the technique to be prone to errors. Interestingly, although this review does not focus on machine learning, there are only few studies that have adopted it as an alternative to statistical analysis in the assessment of muscle fatigue, torque, and force. The results confirm the need for further investigation on the use of sophisticated computations of features of MMG signals from electrically stimulated muscles in muscle function assessment and assistive technology such as prosthetics control.


2015 ◽  
Vol 10 (2) ◽  
pp. 204-210 ◽  
Author(s):  
Matthew Weston ◽  
Angela E. Hibbs ◽  
Kevin G. Thompson ◽  
Iain R. Spears

Purpose:To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming.Methods:Twenty national-level junior swimmers (10 male and 10 female, 16 ± 1 y, 171 ± 5 cm, 63 ± 4 kg) participated in the study. Group allocation (intervention [n = 10], control [n = 10]) was based on 2 preexisting swim-training groups who were part of the same swimming club but trained in different groups. The intervention group completed the core training, incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula, 3 times/wk for 12 wk. While the training was performed in addition to the normal pool-based swimming program, the control group maintained their usual pool-based swimming program. The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function.Results:Compared with the control group, the core-training intervention group had a possibly large beneficial effect on 50-m swim time (–2.0%; 90% confidence interval –3.8 to –0.2%). Moreover, it showed small to moderate improvements on a timed prone-bridge test (9.0%; 2.1–16.4%) and asymmetric straight-arm pull-down test (23.1%; 13.7–33.4%), and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction.Conclusion:This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance.


Sign in / Sign up

Export Citation Format

Share Document