Fig 1 - uploaded by Julien Gondin
Content may be subject to copyright.
Plantar Xexor MVC torque at pre-, post-and detraining for TG and CG subjects. Mean values § SE. **SigniWcantly higher than pre-training at P < 0.01
Source publication
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...
Similar publications
In a previous study, Achilles tendon vibrations were enough to improve the triceps surae (TS) activation capacities and also to slightly increase TS Hoffmann reflex (H-reflex) obtained by summing up soleus (Sol) and gastrocnemii (GM and GL) EMGs. The purpose of the present study was to analyze separately Sol and GM or GL reflexes to account for dif...
Citations
... Several studies demonstrated the benefits of WB-EMS on muscular strength in moderately trained young adults [14], post-menopausal women [15], obese women [16], athletes [17] and patients with neurological disorders [18]. However, the simultaneous stimulation of large muscle groups combined with high-frequency electrical stimulation can excessively elevate the creatine kinase (CK) levels and potentially lead to rhabdomyolysis [19], increasing the risk of acute renal failure [20] and muscular and cardiac problems [21]. Several studies [22,23] demonstrated a significant increase in CK levels, up to a thousand-fold (240,000 U/L) compared to the normal levels (<180 U/L). ...
Strength training elicits benefits both in performance and on a psychological level in women, such as increased muscle strength and improved self-esteem. Whole-body electromyostimulation (WB-EMS) could be a training strategy for enhancing muscular strength. The aim of this study was to assess the acute effects of a single session of WB-EMS superimposed over classic resistance training on isometric strength, endurance strength and flexibility. Furthermore, the safety of the protocol was assessed by monitoring the levels of creatine kinase (CK) 48 h after the training protocol was completed. Sixteen active women (aged 22.06 ± 1.88) were randomly assigned to an experimental group (EG) (n = 8) and a control group (CG) (n = 8). The EG performed four sets of 12 repetitions of three strength exercises with superimposed WB-EMS, while the CG performed the same protocol without WB-EMS. RM-ANOVA showed a significant time*group interaction on posterior kinetic chain extensors’ mean and peak strength in the EG (F(1,14) = 10.036; p = 0.007; and F(1,14) = 20.719; p < 0.001; respectively). A significant time*group interaction was found in the sit and reach test for the EG (F(1,14) = 10.362; p = 0.006). Finally, ANOVA performed on the CK levels showed no significant difference between the groups (F(1,14) = 0.715; p = 0.412). WB-EMS training led to an immediate improvement in strength performance and flexibility, and this protocol was shown to be safe in terms of CK levels, 48 h after completing the training protocol.
... However, electrostimulation has also important disadvantages, such as Golgi tendon organ and myotatic reflex inhibition, which can lead to an increased injury risk if its use is not adequate [15]. Moreover, the functional transfer of these gains into sports movements is more relevant [16] and, in order to achieve this functional transfer and to develop higher force and power, electrostimulation has to be combined or superimposed with sport-specific exercises [17,18]. ...
Introduction. The aim of the present study was to investigate the effects of a 6-week low intensity plyometric training (PT) + whole-body electrostimulation (WBES) combined program, compared with traditional PT, on vertical jump performance, 20 m sprint-time and handgrip strength. Material and methods. 10 male and 10 female Physical Education students were randomly allocated to a control (CON) or an experimental (EXP) group. Both groups performed a 6-week low intensity PT 3 days per week, and during the third day, PT was simultaneously combined with WBES in the EXP group. Countermovement jump (CMJ) height, CMJ peak power, 20 m sprint-time and handgrip strength were measured before (pre-test) and after (post-test) the training period. Repeated measures ANOVA was performed to identify differences after the training program. Effect sizes (ES)
were assessed using Hedge’s g. Results. No significant differences between groups were observed at post-test. CMJ height and CMJ peak power significantly increased in both groups, with greater ES in the EXP group (p < 0.001, g = 0.68; p < 0.001, g = 0.70,
respectively). 20 m sprint-time significantly improved in both groups, with greater ES in the CON group (p < 0.001, g = -1.68). Handgrip strength also increased in both groups, but ES were minimal. Conclusions. Both training methods demonstrated to be a good strategy to improve CMJ performance and 20 m sprint-time. The most effective training method for improving CMJ performance was PT + WBES combined program, and traditional PT obtained better results in 20 m sprint-time.
... Eight men (age: 27.0 ± 3.5 yrs, height: 176.5 ± 7.6 cm, body weight: 76.2 ± 11.2 kg) participated in the present study (5 subjects were right leg dominant). This sample size was determined by a preliminary power analysis (α = 0.05, 1-β = 0.90), based on previously published data a showing significant increase in MVC using a similar high frequency NMES training protocol [10][11][12]. MVC parameter was chosen for the sample size as opposed to tendon mechanical properties as according to the previous findings [6,7]. ...
It remains unclear whether neuromuscular electrical stimulation can induce sufficient tendon stress to lead to tendon adaptations. Thus, we investigated the effect of such a training program on the triceps surae muscle following the morphological and mechanical properties of the Achilles tendon. Eight men participated in a 12-week high-frequency neuromuscular electrical stimulation training program of the triceps surae muscle under isometric conditions. Ultrasonography was used pre- and post-intervention to quantify cross-sectional area, free length, and total length of the Achilles tendon, as well as the myotendinous junction elongation during a maximal isometric ramp contraction under plantar flexion. Neuromuscular electrical stimulation training does not lead to changes in Achilles tendon free and total length, cross-sectional area, or maximal elongation capacity. However, a significant increase was evidenced in maximal tendon force post-training (+25.2%). Hence, Young's Modulus and maximal stress were significantly greater after training (+12.4% and +23.4%, respectively). High-frequency neuromuscular electrical stimulation training induces repeated stress sufficient to lead to adaptations of mechanical properties of the Achilles tendon. Thus, this training technique may be of particular interest as a new rehabilitation method in tendinopathy management or to counteract the effect of hypo-activity.
... In the simplest case, it is not surprising that several sessions of NMES can increase the strength of target muscles (6,11,28,43,50,136), but this result can be quite variable (4, 21, 39, 95,122). Although the strength gains appear to be mediated by increases in the level of muscle activation (6, 39, 70,90), several weeks of NMES can induce adaptations in muscle-fiber properties (55,152). One unexpected outcome of these interventions is the capacity of NMES to increase the strength of non-targeted muscles. ...
The generation of action potentials in intramuscular motor and sensory axons in response to an imposed external current source can evoke muscle contractions and elicit widespread responses throughout the nervous system that impact sensorimotor function. The benefits experienced by individuals exposed to several weeks of treatment with electrical stimulation of muscle suggest that the underlying adaptations involve several physiological systems, but little is known about the specific changes elicited by such interventions.
... Although Malatesta et al. [23] found an increase in SJ and CMJ after 4-week EMS training, they didn't find any increases after 10days of EMS training. Jubeau et al. [26] explained their result appeared after EMS as the early (increasing muscle activation and EMG activity) and late adaptation (an increase in the amplitude of the spinal reflex and decrease in co-activation) of the nervous system. Maletesta et al. [23] indicated that EMS caused the increase in neural drive or preferable activation of rapid muscle fibers. ...
Purpose: Electromyostimulation is a popular training to increase muscle strength during the last years. The aim of this study was to investigate effects of electromyostimulation training on jumping and muscle strength in football players. Material: Volunteered 23 football players between the ages of 18 to 24 were divided into experimental and control groups with simple random sampling. Both groups continued to regular training. Experimental group had additional electromyostimulation training for 6-week, 3-time a week, and 20min a day. Pre- and post-training squat and countermovement jumps, peak torques of dominant and non-dominant knee extensor and flexor muscles were tested. Angular velocities of isokinetic dynamometer were 60, 180, and 300ºs-1. Pre- and post-test comparisons within the groups were analyzed. Results: There were no significant differences between pre- and post-test for isokinetic knee strength parameters at all angular velocities of EG. However, control group had significant pre- and post-test differences in dominant and non-dominant knee extension and flexion peak torque values. Conclusions: EMS and regular training in-season had no effect on the isokinetic strength parameters. On the other hand, the regular training in-season has increased isokinetic strength. Electromyostimulation training additional to regular training may have detrimental effects on outcomes of concurrent training in football players.
... This rather long contraction duration was chosen to enable time for extraforce development (Dean et al. 2007). As WPHF-evoked contractions were longer than classical NMES contractions, a lower number of contractions were considered to achieve a comparable stimulation duration per session as classically employed [i.e., 200 s in the present study vs. 160-180 s in (Gondin et al. 2006b, c;Jubeau et al. 2006;Maffiuletti et al. 2003)]. Each contraction was separated from the previous one by 40 s, i.e., duty cycle was 33% (Neyroud et al. 2014). ...
... Previous studies showed that 3-5 weeks of classical NMES training (with evoked forces ranging from 50 to 80% MVC) (Gondin et al. 2006a, b;Jubeau et al. 2006;Maffiuletti et al. 2002;Pichon et al. 1995) induced gains in MVC forces (~ 20%) that could be attributed to increased neural drive as evidenced by increases in VAL, RMS max /M max and V/M sup alongside with an unchanged H max /M max ratio (Gondin et al. 2006a, b;Jubeau et al. 2006;Maffiuletti et al. 2002). In contrast to these previous studies using classical NMES paradigms, our findings revealed no neural adaptations (i.e., no changes in VAL, RMS max /M max or V/M sup ) following 3 weeks of WPHF NMES. ...
... Previous studies showed that 3-5 weeks of classical NMES training (with evoked forces ranging from 50 to 80% MVC) (Gondin et al. 2006a, b;Jubeau et al. 2006;Maffiuletti et al. 2002;Pichon et al. 1995) induced gains in MVC forces (~ 20%) that could be attributed to increased neural drive as evidenced by increases in VAL, RMS max /M max and V/M sup alongside with an unchanged H max /M max ratio (Gondin et al. 2006a, b;Jubeau et al. 2006;Maffiuletti et al. 2002). In contrast to these previous studies using classical NMES paradigms, our findings revealed no neural adaptations (i.e., no changes in VAL, RMS max /M max or V/M sup ) following 3 weeks of WPHF NMES. ...
Purpose
No studies have evaluated the potential benefits of wide-pulse high-frequency (WPHF) neuromuscular electrical stimulation (NMES) despite it being an interesting alternative to conventional NMES. Hence, this study evaluated neuromuscular adaptations induced by 3 weeks of WPHF NMES.
Methods
Ten young healthy individuals (training group) completed nine sessions of WPHF NMES training spread over 3 weeks, whereas seven individuals (control group) only performed the first and last sessions. Plantar flexor neuromuscular function (maximal voluntary contraction (MVC) force, voluntary activation level, H reflex, V wave, contractile properties) was evaluated before the first and last training sessions. Each training session consisted of ten 20-s WPHF NMES contractions (pulse duration: 1 ms, stimulation frequency: 100 Hz) interspaced by 40 s of recovery and delivered at an intensity set to initially evoke ~ 5% of MVC force. The averaged mean evoked forces produced during the ten WPHF NMES-evoked contractions of a given session as well as the sum of the ten contractions force time integral (total FTI) were computed.
Results
Total FTI (+ 118 ± 98%) and averaged mean evoked forces (+ 96 ± 91%) increased following the 3-week intervention (p < 0.05); no changes were observed in the control group. The intervention did not induce any change (p > 0.05) in parameters used to characterize plantar flexor neuromuscular function.
Conclusion
Three weeks of WPHF NMES increased electrically evoked forces but induced no other changes in plantar flexor neuromuscular properties. Before introducing WPHF NMES clinically, optimal training program characteristics (such as frequency, duration and intensity) remain to be identified.
... For example, Clark et al. (2013) found that differences in maximal walking speed of older adults were associated with the rate of increase in force for the plantar flexors and EMG for medial gastrocnemius during rapid isometric contractions and not the cross-sectional areas of triceps surae, quadriceps femoris, or hamstrings. Consistent with this interpretation, four weeks of NMES (16 sessions) applied to the plantar flexors of young men produced significant increases in EMG amplitude during MVCs, especially for lateral gastrocnemius (Jubeau et al., 2006). Moreover, the application of NMES to quadriceps femoris during rehabilitation after total knee arthroplasty resulted in less of a reduction in performance on functional tests (stair climbing, timed up-and-go, and 6-min walk) than standardof-care exercises and a faster recovery than that of muscle strength (Stevens-Lapsley et al., 2012). ...
Declines in mobility with advancing age are often associated with a reduction in the use of lower leg muscles. We examined the influence of two interventions that involved neuromuscular electrical stimulation (NMES) applied to the triceps surae muscles on the mobility and muscle function of older adults. Thirty healthy older adults (73.5 ± 4.8 yrs) participated in a 6-week intervention comprising 3 weekly sessions of either narrow- or wide-pulse NMES. Motor function was assessed at Weeks 0, 4, 7, and 10. There were no statistically significant differences in the changes in mobility for the two groups of participants, so the data for the two groups were combined to examine changes across time. Time to walk 400 m decreased and maximal walking speed increased after 3 wks of NMES (Week 4) but did not change further at Weeks 7 and 10. In contrast, time to complete the chair-rise and rapid-step tests decreased progressively up to Week 7 but did not change further at Week 10. Moreover, the increase in plantar flexor strength was only observed at Week 7. NMES can elicit improvements in the motor function of older adults, but the time course of the adaptations differs across the mobility tests.
... However, the neural effects of NMES are under extensive investigation since several decades and are thought to mainly occur at the supraspinal level. [38][39][40][41][42][43][44] Therefore, it may be hypothesized that NMES increased the contralateral neural drive through one or more of the following mechanisms: increased intracortical facilitation, decreased intracortical inhibition, increased interhemispheric inhibition, increased corticospinal excitability. Which of these mechanisms was mainly responsible for the observed findings remains to be elucidated. ...
Background:
The "contralateral effect" phenomenon refers to the strength gain in the opposite, untrained homonymous muscle following unilateral training. Previous studies showed that neuromuscular electrical stimulation (NMES) of the right quadriceps facilitated maximal voluntary strength and efferent neural drive of the left knee extensors, while no previous study investigated the contralateral effect elicited by focal muscle vibration.
Aim:
To investigate whether quadriceps NMES and focal vibration, when applied unilaterally, have the same potential to enhance the contralateral muscle strength and the associated neural drive.
Design:
Randomised controlled experimental study.
Setting:
University laboratory.
Population:
Healthy subjects.
Methods:
Subjects completed several maximal voluntary contractions (MVCs) of the left quadriceps (tested muscle) while the right quadriceps (treated muscle) received no conditioning stimulation (control condition), NMES or focal vibration. Paired supramaximal stimuli were delivered to the left quadriceps during and immediately after the MVCs to assess voluntary activation. The EMG activity of vastus lateralis, vastus medialis, and rectus femoris muscles of the left quadriceps was also concomitantly recorded.
Results:
MVC torque and voluntary activation of the left quadriceps increased during contralateral NMES and vibration. A remarkable inter-individual variability was observed in the contralateral effect of NMES and vibration. In fact, MVC and voluntary activation increases were particularly evident in subjects "responders" to both treatments (who showed NMES-elicited increases in MVC and voluntary activation of 22.5% and 15.8%, respectively, and vibration-elicited increases of 13.1% and 10.7%, respectively). Moreover, we found that the increases in voluntary activation and EMG activity elicited by NMES were higher than those elicited by focal vibration. We also found that voluntary activation increases were higher in subjects presenting lower baseline levels of voluntary activation.
Conclusions:
The short-duration unilateral application of quadriceps NMES and focal vibration increased MVC torque and efferent neural drive of the contralateral homologous muscle in healthy subjects.
Clinical rehabilitation impact:
As the two physical therapy modalities can be useful to maximize motor unit recruitment contralaterally to the side of application, they could be incorporated in rehabilitation protocols when unilateral voluntary contractions are uncomfortable, painful or not feasible.
... Extreme increases in CK concentration constitute a potential risk of renal damage [5]. Due to the high correlation of CK to myoglobin [12,13], in the worst case there may even be acute renal failure (ARF) [14,15], at least in persons with prevalent renal impairment. Besides ARF, rhabdomyolysis may trigger more acute effects (e.g. ...
Recently extreme increases in serum creatine-kinase (CK) concentration after initial whole-body electromyostimulation (WB-EMS) were reported that indicating a severe (exertional) rhabdomyolysis. Thus our aim was (1) to verify the reported WB-EMS induced CK-increases, (2) to determine the corresponding consequences for health and (3) to assess physiological CK-adaptation to frequent WB-EMS. Thirty-seven eligible WB-EMS novices and six marathon runners living in the Nürnberg-Erlangen area were included. Trail-I and trial-II determined the effect of one single WB-EMS session to exertion (20 min) on electrolytes, muscular and renal parameters; trial-III evaluated the effect of once a week WB-EMS application for 10 weeks on CK-kinetics. Blood samples of corresponding serum parameters were drawn before, immediately after and 24, 48, 72, and 96 h post WB-EMS exercise. After WB-EMS, serum CK-levels increased by the 96-fold (peak-CK: 23.940 ± 24.545 U/L), 8.5-fold higher compared with CK-increases after a marathon run. However, we did not observe any relevant health consequences with respect to cardiac and renal burdens. Further, following the repeated bout effect, 10 weeks of WB-EMS resulted in a 21-fold reduction of CK-concentration (<1.000 U/l) compared with the baseline test. We confirmed there were exceptionally high CK increases after initial WB-EMS when the intensity was (too) high, but this was ameliorated by a rapid and profound “repeated bout effect” after 10 weeks of WB-EMS application. Although we did not detect any negative consequences in this healthy, well-prepared and medically supervised cohort, initial WB-EMS application to exertion should be strictly avoided in order to prevent hepatic, renal and cardiac incidents.
... Therefore such a movement control relies heavily on the storage capacity of the central nervous system (Malatesta et al., 2003;Van Zandwijk et al., 2000). Delayed optimization of such templates in the central nervous system can delay vertical jump development (late neural adaptation) after EMS training (Jubeau et al., 2006;Maffiuletti et al., 2002b). However, jump performance and isokinetic strength improvements were obtained immediately after the LB-EMS application in the present study. ...
Electromyostimulation is commonly used for potentiation of muscle strength to supplement voluntary muscle contractions. However, the acute effects of the lower body electromyostimulation on muscle strengthening are poorly known. Fourteen moderately trained men exposed to three lower body electromyostimulation sessions in nonconsecutive days under experimental conditions (30Hz, 100Hz) and control condition (0Hz). Each subject participated in post-tests including squat jump, countermovement jump and dominant concentric knee extension-flexion isokinetic strength at 60, 180, 300°s-1.All tests performed 90 seconds after a single bout of lower body electromyostimulation with 90° static squat position for 16 seconds (4s Electromyostimulation/4s rest) at maximal tolerated current intensity. Statistical analysis have shown that there are significant increases in jump heights (p<0.05), rating perceived exertion (p≤0.001) and knee flexion torques at 180 and 300°s-1 angular velocities (p<0.05) for acute electromyostimulation with two experimental conditions compared to control condition. Postactivation potentiation effect of conditioning contractions can be responsible for mechanism under these significant differences. However, there were no significant differences between low and high frequencies regarding 60°, 180°, 300°s-1 extension and 60os-1 flexion knee isokinetic torques (p>0.05) and all jump values (p>0.05). In conclusion, lower body electromyostimulation at low or high frequencies can increase explosive strength regarding high-speed flexion torques and jump height in acute phase of moderately trained men.
