Journal
NEUROSCIENCE LETTERS
Volume 356, Issue 1, Pages 61-65Publisher
ELSEVIER SCI IRELAND LTD
DOI: 10.1016/j.neulet.2003.09.052
Keywords
global effort; isometric force; fatigue; postural muscles; electromyography
Categories
Ask authors/readers for more resources
The purpose of this study was to explore whether global efforts stop as a consequence of postural muscle exhaustion. To this end, seated adults were asked to exert 75% maximal voluntary contractions bimanual push efforts until exhaustion. A dynamometer was used to measure the horizontal force exerted on a bar (Fx) and a custom-designed force plate measured the antero-posterior displacement of the centre of pressure (Xp). Electromyograms were picked up by bipolar surface electrodes from the primum movens (serratus anterior) and four postural muscles (trapezius superior, erectores spinae, rectus abdominis, rectus femoris). Root mean square and mean power frequency were calculated over 2-s intervals and compared to corresponding Fx and Xp values. It was shown that the effort stops as a consequence of exhaustion of postural muscles (rectus abdominis and rectus femoris), and not of the primum movens. It is concluded that postural muscles make a major contribution to global efforts, in that they allow compliance to biomechanical requirements, that is, to preserve the distance between the centre of pressure and the centre of gravity, which must be proportional to the external force. (C) 2003 Elsevier Ireland Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available