Muscle fatigue increases beta-band coherence between the firing times of simultaneously active motor units in the first dorsal interosseous muscle

Files in This Item:
 File SizeFormat
Downloadinsight_publication.pdf1.3 MBAdobe PDF
Title: Muscle fatigue increases beta-band coherence between the firing times of simultaneously active motor units in the first dorsal interosseous muscle
Other Titles: Muscle fatigue increases intramuscular motor unit coherence
Authors: McManus, Lara M.Hu, XiaogangRymer, WilliamSuresh, NinaLowery, Madeleine M.
Permanent link:
Date: 1-Jun-2016
Online since: 2017-06-01T01:00:12Z
Abstract: Synchronization between the firing times of simultaneously active motor units (MUs) is generally assumed to increase during fatiguing contractions. To date, however, estimates of MU synchronization have relied on indirect measures, derived from surface electromyographic (EMG) interference signals. This study used intramuscular coherence to investigate the correlation between MU discharges in the first dorsal interosseous muscle during and immediately following a submaximal fatiguing contraction, and after rest. Coherence between composite MU spike trains, derived from decomposed surface EMG, were examined in the delta (14 Hz), alpha (812 Hz), beta (1530 Hz), and gamma (3060 Hz) frequency band ranges. A significant increase in MU coherence was observed in the delta, alpha, and beta frequency bands postfatigue. In addition, wavelet coherence revealed a tendency for delta-, alpha-, and beta-band coherence to increase during the fatiguing contraction, with subjects exhibiting low initial coherence values displaying the greatest relative increase. This was accompanied by an increase in MU short-term synchronization and a decline in mean firing rate of the majority of MUs detected during the sustained contraction. A model of the motoneuron pool and surface EMG was used to investigate factors influencing the coherence estimate. Simulation results indicated that changes in motoneuron inhibition and firing rates alone could not directly account for increased beta-band coherence postfatigue. The observed increase is, therefore, more likely to arise from an increase in the strength of correlated inputs to MUs as the muscle fatigues.
Funding Details: Irish Research Council
Type of material: Journal Article
Publisher: American Psychological Society
Journal: Journal of Neurophysiology
Volume: 115
Issue: 6
Start page: 2830
End page: 2839
Copyright (published version): 2016 The American Psychological Society
Keywords: Motor unit coherenceIsometric fatigueIntramuscular coherenceBeta-band coherenceShort-term synchronization
DOI: 10.1152/jn.00097.2016
Language: en
Status of Item: Peer reviewed
This item is made available under a Creative Commons License:
Appears in Collections:Electrical and Electronic Engineering Research Collection
Insight Research Collection

Show full item record

Citations 20

Last Week
Last month
checked on Sep 11, 2020

Page view(s) 50

Last Week
Last month
checked on Sep 26, 2022

Download(s) 50

checked on Sep 26, 2022

Google ScholarTM



If you are a publisher or author and have copyright concerns for any item, please email and the item will be withdrawn immediately. The author or person responsible for depositing the article will be contacted within one business day.