The influence of eccentric exercise-induced muscle weakness on the history dependence of force

Date
Authors
Contento, Vincenzo
Journal Title
Journal ISSN
Volume Title
Publisher
University of Guelph
Abstract

Following active lengthening or shortening, force production in subsequent isometric contractions are increased (residual force enhancement; rFE) or decreased (residual force depression; rFD), respectively, compared to fixed-end isometric reference contractions at same muscle lengths and activation levels. These intrinsic properties of muscle are collectively known as the history dependence of force. The purpose of this thesis was to investigate how rFE and rFD are modified in a weakened state. Participants performed electrically stimulated, and submaximal and maximal voluntary contractions (MVC) prior to, and following eccentric exercise. Following eccentric exercise; MVC torque was decreased, prolonged low frequency force depression was present, and both rFE and rFD increased for all maximal and submaximal conditions. Thus, rFE seems to be increased due to concomitant maintenance and reductions in passive and active forces, respectively. Furthermore, we speculate that the increase in rFD is due to mechanical, but not metabolic alterations in the weakened state.

Description
Keywords
history dependence of force, residual force enhancement, residual force depression, active lengthening, active shortening, eccentric exercise, weakness, tibialis anterior
Citation
Contento, V.S. and Power G.A. (Under Review). Eccentric exercise-induced muscle weakness amplifies the history dependence of force. Eur. J. App. Physiol.