Document Detail


Quantitative analysis of the limits of stability in sitting.
MedLine Citation:
PMID:  20841617     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study defines the limits of stability in sitting, and quantitatively assesses two measures of postural control relative to these limits. Young, healthy subjects sat, feet unsupported, on an elevated force plate. The limits of stability were determined by a least square fit of an ellipse to the center of pressure (CoP) excursion during maximal leaning in 8 directions. These were highly symmetrical and centered within the base of support. The ellipses had a mean eccentricity of 0.66 (major axis in the sagittal plane) and covered an area approximately 1/3 of the base of support. The CoP was then monitored over 4 min of quiet sitting, during which the postural sway covered an area<0.05% of the limits of stability and was closely centered within the latter. Finally, target-directed trunk movements were performed, in 5 directions, at 4 movement speeds and 3 target distances. Increased target distance and movement speed both decreased the margin of stability (distance between the CoP and the limits of stability), as did movement in the frontal plane, reflecting the eccentricity of the limits of stability. These combined findings support the validity of this quantitative method of defining the limits of stability in sitting, for healthy individuals.
Authors:
Richard A Preuss; Milos R Popovic
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied biomechanics     Volume:  26     ISSN:  1065-8483     ISO Abbreviation:  J Appl Biomech     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-09-15     Completed Date:  2010-11-02     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9315240     Medline TA:  J Appl Biomech     Country:  United States    
Other Details:
Languages:  eng     Pagination:  265-72     Citation Subset:  IM    
Affiliation:
Rehabilitation Engineering Laboratory, Lyndhurst Centre, Toronto Rehabilitation Institute, Toronto, ON, Canada.
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MeSH Terms
Descriptor/Qualifier:
Adult
Anthropometry
Female
Humans
Least-Squares Analysis
Male
Middle Aged
Postural Balance / physiology*
Reference Values
Thorax / physiology
Grant Support
ID/Acronym/Agency:
129179//Canadian Institutes of Health Research

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


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