Extra Forces induced by wide-pulse, high-frequency electrical stimulation: Occurrence, magnitude, variability and underlying mechanisms.

Details

Serval ID
serval:BIB_60EB9CF59375
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Extra Forces induced by wide-pulse, high-frequency electrical stimulation: Occurrence, magnitude, variability and underlying mechanisms.
Journal
Clinical Neurophysiology
Author(s)
Wegrzyk J., Fouré A., Vilmen C., Ghattas B., Maffiuletti N.A., Mattei J.P., Place N., Bendahan D., Gondin J.
ISSN
1872-8952 (Electronic)
ISSN-L
1388-2457
Publication state
Published
Issued date
2015
Peer-reviewed
Oui
Volume
126
Number
7
Pages
1400-1412
Language
english
Notes
Publication types: Journal Article Publication Status: ppublish
Abstract
OBJECTIVE: In contrast to conventional (CONV) neuromuscular electrical stimulation (NMES), the use of "wide-pulse, high-frequencies" (WPHF) can generate higher forces than expected by the direct activation of motor axons alone. We aimed at investigating the occurrence, magnitude, variability and underlying neuromuscular mechanisms of these "Extra Forces" (EF).
METHODS: Electrically-evoked isometric plantar flexion force was recorded in 42 healthy subjects. Additionally, twitch potentiation, H-reflex and M-wave responses were assessed in 13 participants. CONV (25Hz, 0.05ms) and WPHF (100Hz, 1ms) NMES consisted of five stimulation trains (20s on-90s off).
RESULTS: K-means clustering analysis disclosed a responder rate of almost 60%. Within this group of responders, force significantly increased from 4% to 16% of the maximal voluntary contraction force and H-reflexes were depressed after WPHF NMES. In contrast, non-responders showed neither EF nor H-reflex depression. Twitch potentiation and resting EMG data were similar between groups. Interestingly, a large inter- and intrasubject variability of EF was observed.
CONCLUSION: The responder percentage was overestimated in previous studies.
SIGNIFICANCE: This study proposes a novel methodological framework for unraveling the neurophysiological mechanisms involved in EF and provides further evidence for a central contribution to EF in responders.
Pubmed
Web of science
Create date
29/06/2015 12:24
Last modification date
20/08/2019 14:18
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