Effect of pain location on spatial reorganisation of muscle activity

Hug, François, Hodges, Paul W. and Tucker, Kylie J. (2013) Effect of pain location on spatial reorganisation of muscle activity. Journal of Electromyography and Kinesiology, 23 6: 1413-1420. doi:10.1016/j.jelekin.2013.08.014

Author Hug, François
Hodges, Paul W.
Tucker, Kylie J.
Title Effect of pain location on spatial reorganisation of muscle activity
Journal name Journal of Electromyography and Kinesiology   Check publisher's open access policy
ISSN 1050-6411
Publication date 2013-12
Sub-type Article (original research)
DOI 10.1016/j.jelekin.2013.08.014
Open Access Status
Volume 23
Issue 6
Start page 1413
End page 1420
Total pages 8
Place of publication Camden, London, United Kingdom
Publisher Elsevier
Collection year 2014
Language eng
Formatted abstract
Introduction We aimed to determine whether the changes in muscle activity (in terms of both gross electromyography (EMG) and motor unit (MU) discharge characteristics) observed during pain are spatially organized with respect to pain location within a muscle which is the main contributor of the task.

Methods Surface and fine-wire EMG was recorded during matched low-force isometric plantarflexion from soleus (from four quadrants with fine-wire EMG and from the medial/lateral sides with surface EMG), both gastrocnemii heads, peroneus longus, and tibialis anterior. Four conditions were tested: two control conditions that each preceded contractions with pain induced in either the lateral (PainL) or medial (PainM) side of soleus.

Results Neither the presence (p = 0.28) nor location (p = 0.19) of pain significantly altered gross muscle activity of any location (lateral/medial side of soleus, gastrocnemii, peroneus longus and tibialis anterior). Group data from 196 MUs show redistribution of MU activity throughout the four quadrants of soleus, irrespective of pain location. The significant decrease of MU discharge rate during pain (p < 0.0001; PainL: 7.3 ± 0.9–6.9 ± 1.1 Hz, PainM: 7.0 ± 1.1 to 6.6 ± 1.1 Hz) was similar for all quadrants of the soleus (p = 0.43), regardless of the pain location (p = 0.98). There was large inter-participant variation in respect to the characteristics of the altered MU discharge with pain.

Conclusion Results from both surface and fine-wire EMG recordings do not support the hypothesis that muscle activity is reorganized in a simple systematic manner with respect to pain location.
Keyword Motor unit recruitment
Discharge rate
Triceps surae
Hypertonic saline
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
Official 2014 Collection
School of Health and Rehabilitation Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 9 times in Scopus Article | Citations
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Created: Wed, 13 Nov 2013, 22:00:49 EST by Ms Kylie Tucker on behalf of School of Health & Rehabilitation Sciences