External abdominal oblique muscle ultrasonographic thickness changes is not an appropriate surrogate measure of electromyographic activity during isometric trunk contractions
Type de document
Études primaires
Année de publication
2015
Langue
Anglais
Titre de la revue
Journal of Back and Musculoskeletal Rehabilitation
Première page
229
Dernière page
238
Résumé
Background:
The function of specific abdominal muscles can be assessed using both electromyography (EMG) and ultrasound imaging (USI) thickness measures. However, the relationship between these two measurements is not conclusive during sitting isometric trunk efforts.
Objective:
This study was conducted to assess the relationship between USI thickness and EMG amplitude measures of the right external oblique (EO) muscle during isometric efforts in the sitting position.
Method:
Eighteen subjects performed ramp isometric efforts progressing from 0 to 50% of their maximal voluntary contraction (MVC) in three trunk directions on a dynamometer: (1) forward flexion; (2) right lateral flexion; and (3) left axial rotation. USI and surface EMG amplitude measures of the EO muscle were recorded concomitantly and both normalized against rest values and maximal EMG, respectively.
Results:
EO muscle was significantly more activated (p < 0.0001) during forward flexion (42% on average) and axial rotation (35%) than during lateral flexion (24%). Non-significant (r = 0.01; P = 0.979) to highly significant ((r = 0.98; P < 0.0001) and negative and positive Pearson correlations were observed between EMG and EO thickness measures for both flexion and rotation directions.
Conclusion:
The negative correlations between EMG and USI measures as well as the great variability of these correlations across individuals suggest that USI is not a valid measures of EO muscle activity. USI thickness measures should be interpreted with great caution in research and clinical settings.
Mots-clés
Effort isométrique, Isometric exercise, Électromyographie, Electromyography, Ultrason, Ultrasound, Épreuve de la force musculaire, Muscle testing, Posture assise, Sitting posture, Mécanique humaine, Body mechanics
Numéro de projet IRSST
n/a
Citation recommandée
Rabello, L. M., Gagnon, D. H., da Silva, R. A., Paquette, P. et Larivière, C. (2015). External abdominal oblique muscle ultrasonographic thickness changes is not an appropriate surrogate measure of electromyographic activity during isometric trunk contractions. Journal of Back and Musculoskeletal Rehabilitation, 28(2), 229-238. https://doi.org/10.3233/BMR-140508