2UBC - University of British Columbia (Vancouver Campus, , 2329 West Mall, Vancouver, BC, V6T 1Z4 /
Okanagan Campus, 3333 University Way, Kelowna, BC, V1V 1V7 - Canada)
Abstract : During maximal contractions, the sum of forces exerted by homonymous muscles unilaterally is typically higher than the sum of forces exerted by the same muscles bilaterally. However, the underlying mechanism(s) of this phenomenon, which is known as the bilateral strength deficit, remain equivocal. One potential factor that has received minimal attention is the contribution of body adjustments to bilateral and unilateral force production. The purpose of this study was to evaluate the plantar-flexors in an innovative dynamometer that permitted the influence of torque from body adjustments to be adapted. Participants were identically positioned between two setup configurations where torques generated from body adjustments were included within the net ankle torque (locked-unit) or independent of the ankle (open-unit). Twenty healthy adult males performed unilateral and bilateral maximal voluntary isometric plantar-flexion contractions using the dynamometer in the open and locked-unit mechanical configurations. While there was a significant bilateral strength deficit in the locked-unit (p = 0.01), it was not evident in the open-unit (p = 0.07). In the locked-unit, unilateral torque was greater than in the open-unit (p<0.001) and this was due to an additional torque from the body since the electromyographic activity of the agonist muscles did not differ between the two setups (p>0.05). This study revealed that the mechanical configuration of the dynamometer and then the body adjustments caused the observation of a bilateral strength deficit
https://hal-uphf.archives-ouvertes.fr/hal-03464838 Contributor : Mylène DelrueConnect in order to contact the contributor Submitted on : Thursday, April 14, 2022 - 10:51:17 AM Last modification on : Thursday, April 14, 2022 - 11:10:19 AM Long-term archiving on: : Friday, July 15, 2022 - 6:40:23 PM
Emilie Simoneau-Buessinger, Sebastien Leteneur, Anis Toumi, Alexandra Dessurne, François Gabrielli, et al.. Bilateral Strength Deficit Is Not Neural in Origin; Rather Due to Dynamometer Mechanical Configuration. PLoS ONE, Public Library of Science, 2015, 10 (12), pp.e0145077. ⟨10.1371/journal.pone.0145077⟩. ⟨hal-03464838⟩