Muscle Fatigue During Neuromuscular Electrical Stimulation is Dependent on Training: A Basis for Microgravity Musculoskeletal Countermeasure Design

BackgroundNeuromuscular electrical stimulation (NMES) can facilitate the recovery of quadriceps muscle strength after total knee arthroplasty (TKA), yet the optimal intensity (dosage) of NMES and its effect on strength after TKA have yet to be determined.ObjectiveThe primary objective of this study was to determine whether the intensity of NMES application was related to the recovery of quadriceps muscle strength early after TKA. A secondary objective was to quantify quadriceps muscle fatigue and activation immediately after NMES to guide decisions about the timing of NMES during rehabilitation sessions.DesignThis study was an observational experimental investigation.MethodsData were collected from 30 people who were 50 to 85 years of age and who received NMES after TKA. These people participated in a randomized controlled trial in which they received either standard rehabilitation or standard rehabilitation plus NMES to the quadriceps muscle to mitigate strength loss. For the NMES intervention group, NMES was applied 2 times per day at the maximal tolerable intensity for 15 contractions beginning 48 hours after surgery over the first 6 weeks after TKA. Neuromuscular electrical stimulation training intensity and quadriceps muscle strength and activation were assessed before surgery and 3.5 and 6.5 weeks after TKA.ResultsAt 3.5 weeks, there was a significant association between NMES training intensity and a change in quadriceps muscle strength (R2=.68) and activation (R2=.22). At 6.5 weeks, NMES training intensity was related to a change in strength (R2=.25) but not to a change in activation (R2=.00). Furthermore, quadriceps muscle fatigue occurred during NMES sessions at 3.5 and 6.5 weeks, whereas quadriceps muscle activation did not change.LimitationsSome participants reached the maximal stimulator output during at least 1 treatment session and might have tolerated more stimulation.ConclusionsHigher NMES training intensities were associated with greater quadriceps muscle strength and activation after TKA.

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Method to Reduce Muscle Fatigue During Transcutaneous Neuromuscular Electrical Stimulation in Major Knee and Ankle Muscle Groups

Neurorehabilitation and Neural Repair ◽

10.1177/1545968314565463 ◽

2014 ◽

Vol 29 (8) ◽

pp. 722-733 ◽

Cited By ~ 14

Author(s):

Dimitry G. Sayenko ◽

Robert Nguyen ◽

Tomoyo Hirabayashi ◽

Milos R. Popovic ◽

Kei Masani

Keyword(s):

Electrical Stimulation ◽

Muscle Fatigue ◽

Neuromuscular Electrical Stimulation ◽

Ankle Muscle ◽

Muscle Groups

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Wide-pulse-high-frequency neuromuscular stimulation of triceps surae induces greater muscle fatigue compared with conventional stimulation

Journal of Applied Physiology ◽

10.1152/japplphysiol.01015.2013 ◽

2014 ◽

Vol 116 (10) ◽

pp. 1281-1289 ◽

Cited By ~ 23

Author(s):

Daria Neyroud ◽

David Dodd ◽

Julien Gondin ◽

Nicola A. Maffiuletti ◽

Bengt Kayser ◽

...

Keyword(s):

Electrical Stimulation ◽

Muscle Fatigue ◽

Motor Unit ◽

High Frequency ◽

Neuromuscular Electrical Stimulation ◽

Triceps Surae ◽

Voluntary Activation ◽

Activation Level ◽

Paired Stimulation ◽

Voluntary Activation Level

We compared the extent and origin of muscle fatigue induced by short-pulse-low-frequency [conventional (CONV)] and wide-pulse-high-frequency (WPHF) neuromuscular electrical stimulation. We expected CONV contractions to mainly originate from depolarization of axonal terminal branches (spatially determined muscle fiber recruitment) and WPHF contractions to be partly produced via a central pathway (motor unit recruitment according to size principle). Greater neuromuscular fatigue was, therefore, expected following CONV compared with WPHF. Fourteen healthy subjects underwent 20 WPHF (1 ms-100 Hz) and CONV (50 μs-25 Hz) evoked isometric triceps surae contractions (work/rest periods 20:40 s) at an initial target of 10% of maximal voluntary contraction (MVC) force. Force-time integral of the 20 evoked contractions (FTI) was used as main index of muscle fatigue; MVC force loss was also quantified. Central and peripheral fatigue were assessed by voluntary activation level and paired stimulation amplitudes, respectively. FTI in WPHF was significantly lower than in CONV (21,717 ± 11,541 vs. 37,958 ± 9,898 N·s P<0,001). The reductions in MVC force (WPHF: −7.0 ± 2.7%; CONV: −6.2 ± 2.5%; P < 0.01) and paired stimulation amplitude (WPHF: −8.0 ± 4.0%; CONV: −7.4 ± 6.1%; P < 0.001) were similar between conditions, whereas no change was observed for voluntary activation level ( P > 0.05). Overall, our results showed a different motor unit recruitment pattern between the two neuromuscular electrical stimulation modalities with a lower FTI indicating greater muscle fatigue for WPHF, possibly limiting the presumed benefits for rehabilitation programs.

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