Effects of Velocity on Electromyographic, Mechanomyographic, and Torque Responses to Repeated Eccentric Muscle Actions

Ethan C Hill; Terry J Housh; Clayton L Camic; Cory M Smith; Kristen C Cochrane; Nathaniel D M Jenkins; Joel T Cramer; Richard J Schmidt; Glen O Johnson

doi:10.1519/JSC.0000000000001266

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Effects of Velocity on Electromyographic, Mechanomyographic, and Torque Responses to Repeated Eccentric Muscle Actions

Journal article

Peer reviewed

Effects of Velocity on Electromyographic, Mechanomyographic, and Torque Responses to Repeated Eccentric Muscle Actions

Ethan C Hill, Terry J Housh, Clayton L Camic, Cory M Smith, Kristen C Cochrane, Nathaniel D M Jenkins, Joel T Cramer, Richard J Schmidt and Glen O Johnson

Journal of strength and conditioning research, Vol.30(6), pp.1743-1751

06/2016

DOI: 10.1519/JSC.0000000000001266

PMID: 26566165

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Abstract

The purposes of this study were to examine the effects of the velocity of repeated eccentric muscle actions on the torque and neuromuscular responses during maximal isometric and eccentric muscle actions. Twelve resistance-trained men performed 30 repeated, maximal, eccentric, isokinetic muscle actions at randomly ordered velocities of 60, 120, or 180°·s on separate days. Maximal voluntary isometric contractions (MVICs) were performed before (pretest) and after (posttest) the repeated eccentric muscle actions on each day. Eccentric isokinetic peak torque (EIPT) values were the averages of the first 3 and last 3 repetitions of the 30 repeated eccentric muscle actions. During the EIPT and MVIC muscle actions, electromyographic (EMG) and mechanomyographic (MMG) amplitude (EMG AMP and MMG AMP) and mean power frequency (EMG MPF and MMG MPF) values were assessed. These results indicated that the repeated eccentric muscle actions had no effects on EIPT, or the EMG AMP, EMG MPF, or MMG MPF values assessed during the EIPT muscle actions, but decreased MMG AMP. The repeated eccentric muscle actions, however, decreased MVIC torque, and also the EMG AMP and MMG MPF values assessed during the MVIC muscle actions, but increased MMG AMP. The results indicated that the velocity of the repeated eccentric muscle actions affected the MVIC torque responses, but not EIPT or any of the neuromuscular parameters. Furthermore, there are differences in the torque and neuromuscular responses for isometric vs. eccentric muscle actions after repeated eccentric muscle actions.

Accelerometry

Adult

Electromyography - methods

Humans

Isometric Contraction - physiology

Male

Muscle, Skeletal - physiology

Myography - methods

Signal Processing, Computer-Assisted

Torque

Details

Title: Subtitle: Effects of Velocity on Electromyographic, Mechanomyographic, and Torque Responses to Repeated Eccentric Muscle Actions
Creators: Ethan C Hill - University of Wisconsin–La Crosse
Terry J Housh - University of Wisconsin–La Crosse
Clayton L Camic - University of Wisconsin–La Crosse
Cory M Smith - University of Nebraska–Lincoln
Kristen C Cochrane - University of Nebraska–Lincoln
Nathaniel D M Jenkins - University of Nebraska–Lincoln
Joel T Cramer - Nutrition & Health Sciences
Richard J Schmidt - University of Nebraska–Lincoln
Glen O Johnson - University of Nebraska–Lincoln
Resource Type: Journal article
Publication Details: Journal of strength and conditioning research, Vol.30(6), pp.1743-1751
DOI: 10.1519/JSC.0000000000001266
PMID: 26566165
NLM abbreviation: J Strength Cond Res
ISSN: 1064-8011
eISSN: 1533-4287
Language: English
Date published: 06/2016
Academic Unit: Center for Social Science Innovation; Injury Prevention Research Center; Health, Sport, and Human Physiology
Record Identifier: 9984259651502771

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