Changes in neuromuscular function after tasks involving control of EMG versus torque feedback of the same duration.

Details

Serval ID
serval:BIB_B8832829F81E
Type
Article: article from journal or magazin.
Collection
Publications
Title
Changes in neuromuscular function after tasks involving control of EMG versus torque feedback of the same duration.
Journal
Neuroscience Letters
Author(s)
Place N., Martin A., Lepers R.
ISSN
0304-3940 (Print)
ISSN-L
0304-3940
Publication state
Published
Issued date
2006
Volume
394
Number
1
Pages
37-41
Language
english
Abstract
This study was designed to compare alterations in neuromuscular function after two tasks of similar duration involving the control of (1) torque level fixed at 40% maximal voluntary contraction (MVC) torque (torque task) and (2) EMG level when exerting 40% MVC torque on the knee extensor muscles. Ten healthy subjects volunteered to participate in two testing sessions separated by approximately 2 h. Contraction duration for the EMG task was fixed for each subject to the time to task failure of the torque task (104+/-20s). MVC, maximal voluntary activation level, muscle compound action potential (M-wave), peak twitch and potentiated peak doublet were assessed before and immediately after each task using electrical stimulation of the femoral nerve. Average EMG activity of quadriceps muscle increased (p<0.01) during the torque task from 27.7+/-5.4% to 46.2+/-19.3% maximal EMG, whereas torque decreased during the EMG task from 41.5+/-2.9% to 28.9+/-3.8% MVC torque. Alterations in MVC torque (p<0.01) and maximal voluntary activation level (p<0.05) were comparable at termination of the two tasks. Rate of perceived exertion was greater (p<0.05) at the end of the torque task compared to the EMG task. Despite the absence of change in the M-wave for either task, potentiated peak doublet was altered after the torque task (-18+/-14%, p<0.01), whereas there was no change after the EMG task (p>0.05). The absence of peripheral failure at the end of the EMG task could be attributed to (1) a lower intramuscular pressure allowing a lesser accumulation of metabolites and (2) a slower rate of PCr hydrolysis compared to the torque task.
Keywords
Adult, Analysis of Variance, Electric Stimulation/methods, Electromyography, Feedback/physiology, Humans, Male, Muscle Contraction/physiology, Muscle Contraction/radiation effects, Muscle, Skeletal/innervation, Muscle, Skeletal/physiology, Nervous System Physiological Phenomena, Time Factors, Torque
Pubmed
Web of science
Create date
20/09/2013 8:35
Last modification date
20/08/2019 15:26
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