Document Detail


The impact of localized fatigue on contralateral tremor and muscle activity is exacerbated by standing posture.
MedLine Citation:
PMID:  20673732     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Physiological tremor is an inherent feature of the motor system that is influenced by intrinsic (neuromuscular) and/or extrinsic (task) factors. Given that tremor must be accounted for during the performance of many fine motor skills; there is a requirement to clarify how different factors interact to influence tremor. This study was designed to assess the impact localized fatigue of a single arm and stance position had on bilateral physiological tremor and forearm muscle activity. Results demonstrated that unilateral fatigue produced bilateral increases in tremor and wrist extensor activity. For example, fatigue resulted in increases in extensor activity across both exercised (increased 8-10% MVC) and the non-exercised arm (increased 3-7% MVC). The impact of fatigue was not restricted to changes in tremor/EMG amplitude, with altered hand-finger coupling observed within both arms. Within the exercised arm, cross-correlation values decreased (pre-exercise r=0.62-0.64; post-exercise r=0.37-0.43) while coupling increased within the non-exercised arm (pre-exercise r=0.51-0.55; post-exercise r=0.62-0.67). While standing posture alone had no significant impact on tremor/EMG dynamics, the tremor and muscle increases seen with fatigue were more pronounced when standing. Together these results demonstrate that the combination of postural and fatigue factors can influence both tremor/EMG outputs and the underlying coordinative coupling dynamics.
Authors:
S Morrison; J J Sosnoff
Publication Detail:
Type:  Journal Article     Date:  2010-07-31
Journal Detail:
Title:  Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology     Volume:  20     ISSN:  1873-5711     ISO Abbreviation:  J Electromyogr Kinesiol     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-09-29     Completed Date:  2011-01-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9109125     Medline TA:  J Electromyogr Kinesiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  1211-8     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Elsevier Ltd. All rights reserved.
Affiliation:
School of Physical Therapy, Old Dominion University, VA 23529, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Arm / physiology
Electromyography
Female
Humans
Male
Muscle Fatigue / physiology*
Posture / physiology*
Tremor / physiopathology*
Wrist / physiology
Young Adult

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Three-dimensional mandibular motion after closed and open reduction of unilateral mandibular condyla...
Next Document:  Distribution and morphology of the juxtapositions between growth hormone-releasing hormone-(ghrh)-im...