Effects of fatigue and recovery on electromechanical delay during isokinetic muscle actions

Authors

Cory M. Smith, University of Nebraska - LincolnFollow
Terry J. Housh, University of Nebraska-LincolnFollow
Ethan C. Hill, University of Nebraska–LincolnFollow
Josh L. Keller, University of Nebraska - LincolnFollow
Glen O. Johnson, University of Nebraska–Lincoln
Richard J. Schmidt, University of Nebraska–LincolnFollow

ORCID IDs

Cory M. Smith https://orcid.org/0000-0001-9581-1225

Joshua L. Keller https://orcid.org/0000-0003-0756-9358

Date of this Version

2017

Citation

Published in Physiological Measurement 38 (2017), pp 1837–1847.

doi 10.1088/1361-6579/aa8983

Comments

Copyright © 2017 Institute of Physics and Engineering in Medicine; published by IOP Publishing. Used by permission.

Abstract

Objective: To examine muscle-specific differences and the effects of fatigue and recovery on electromechanical delay (EMD) during maximal isokinetic muscle actions.

Approach: Thirteen men performed maximal isokinetic knee extension muscle actions at 60° s⁻¹, pretest, posttest, and after 5 min of recovery from 25 maximal isokinetic knee extensions. The onsets of the electromyographic, mechanomyographic, and force signals were used to identify EMD measures from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF).

Main results: There were posttest increases in all EMD measures for all muscles that returned to pretest levels after 5 min of recovery. There were, however, no differences in EMD measures between the VL and VM. All EMD values from the RF were greater than the VL and VM.

Significance: These findings suggested muscle-specific differences in EMD and that excitation-contraction coupling failure and increased compliance of the series elastic component occurred posttest, but subsided after 5 min of recovery.