Experimental muscle pain increases normalized variability of multidirectional forces during isometric contractions

Salomoni, Sauro E. and Graven-Nielsen, Thomas (2012) Experimental muscle pain increases normalized variability of multidirectional forces during isometric contractions. European Journal of Applied Physiology, 112 10: 3607-3617. doi:10.1007/s00421-012-2343-7

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
UQ341453_OA.pdf Full text (open access) application/pdf 4.55MB 0

Author Salomoni, Sauro E.
Graven-Nielsen, Thomas
Title Experimental muscle pain increases normalized variability of multidirectional forces during isometric contractions
Journal name European Journal of Applied Physiology   Check publisher's open access policy
ISSN 1439-6319
Publication date 2012-10
Sub-type Article (original research)
DOI 10.1007/s00421-012-2343-7
Open Access Status File (Author Post-print)
Volume 112
Issue 10
Start page 3607
End page 3617
Total pages 11
Place of publication Heidelberg, Germany
Publisher Springer
Language eng
Subject 2739 Public Health, Environmental and Occupational Health
2732 Orthopedics and Sports Medicine
2737 Physiology (medical)
Abstract Pain elicits complex adaptations of motor strategy, leading to impairments in the generation and control of steady forces, which depend on muscle architecture. The present study used a cross-over design to assess the effects of muscle pain on the stability of multidirectional (taskrelated and tangential) forces during sustained dorsiflexions, elbow flexions, knee extensions, and plantarflexions. Fifteen healthy subjects performed series of isometric contractions (13-s duration, 2.5, 20, 50, 70% of maximal voluntary force) before, during, and after experimental muscle pain. Three-dimensional force magnitude, angle and variability were measured while the task-related force was provided as feedback to the subjects. Surface electromyography was recorded from agonist and antagonist muscles. Pain was induced in agonist muscles by intramuscular injections of hypertonic (6%) saline with isotonic (0.9%) saline injections as control. The pain intensity was assessed on an electronic visual analogue scale. Experimental muscle pain elicited larger ranges of force angle during knee extensions and plantarflexions (P < 0.03) and higher normalized fluctuations of task-related (P < 0.02) and tangential forces (P < 0.03) compared with control assessments across force levels, while the mean force magnitudes, mean force angle and the level of muscle activity were non-significantly affected by pain. Increased multidirectional force fluctuations probably resulted from multiple mechanisms that, acting together, balanced the mean surface electromyography. Although pain adaptations are believed to aim at the protection of the painful site, the current results show that they result in impairments in steadiness of force.
Keyword Adaptation
Force variability
Isometric force
Motor control
Muscle pain
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Health and Rehabilitation Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 16 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 19 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Thu, 09 Oct 2014, 09:46:19 EST by System User on behalf of School of Health & Rehabilitation Sciences