Influence of inter-electrode distance, contraction type, and muscle on the relationship between the sEMG power spectrum and contraction force.

Détails

ID Serval
serval:BIB_23C03405CF51
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Influence of inter-electrode distance, contraction type, and muscle on the relationship between the sEMG power spectrum and contraction force.
Périodique
European journal of applied physiology
Auteur(s)
Rodriguez-Falces J., Neyroud D., Place N.
ISSN
1439-6327 (Electronic)
ISSN-L
1439-6319
Statut éditorial
Publié
Date de publication
03/2015
Peer-reviewed
Oui
Volume
115
Numéro
3
Pages
627-638
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Résumé
Spectral frequencies of the surface electromyogram (sEMG) increase with contraction force, but debate still exists on whether this increase is affected by various methodological and anatomical factors. This study aimed to investigate the influence of inter-electrode distance (IED) and contraction modality (step-wise vs. ramp) on the changes in spectral frequencies with increasing contraction strength for the vastus lateralis (VL) and vastus medialis (VM) muscles.
Twenty healthy male volunteers were assessed for isometric sEMG activity of the VM and VL, with the knee at 90° flexion. Subjects performed isometric ramp contractions in knee extension (6-s duration) with the force gradually increasing from 0 to 80% MVC. Also, subjects performed 4-s step-wise isometric contractions at 10, 20, 30, 40, 50, 60, 70, and 80% MVC. Interference sEMG signals were recorded simultaneously at different IEDs: 10, 20, 30, and 50 mm. The mean (F mean) and median (F median) frequencies and root mean square (RMS) of sEMG signals were calculated.
For all IEDs, contraction modalities, and muscles tested, spectral frequencies increased significantly with increasing level of force up to 50-60 % MVC force. Spectral indexes increased systematically as IED was decreased. The sensitivity of spectral frequencies to changes in contraction force was independent of IED. The behaviour of spectral indexes with increasing contraction force was similar for step-wise and ramp contractions.
In the VL and VM muscles, it is highly unlikely that a particular inter-electrode distance or contraction modality could have prevented the observation of the full extent of the increase in spectral frequencies with increasing force level.

Mots-clé
Adult, Electrodes, Electromyography/methods, Humans, Isometric Contraction, Male, Muscle Strength, Muscle, Skeletal/physiology
Pubmed
Web of science
Création de la notice
13/03/2015 19:30
Dernière modification de la notice
03/03/2018 14:55
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