Document Detail


Time series analysis of postural responses to combined visual pitch and support surface tilt.
MedLine Citation:
PMID:  21238543     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of using time-series analyses is to provide interpretation of information on curves or functions, such as dynamic, biomechanical data. We evaluated the application of one method of time-series analysis for assessing changes in postural responses when exposed to a continuously rotating visual field combined with a tilted support surface. Functional Principal Component Analysis (fPCA) was applied to center of mass (CoM) trajectories collected from 22 young adults (20-39 y.o.) on a fixed surface or following a 3 degree (30°/s) dorsiflexion tilt of the support surface combined with continuous upward or downward pitch rotation of the visual field at 30 and 45°/s. The usefulness of this analytical tool is that each curve is treated as a distinct observation by itself, allowing for traditional PCA to be applied to the analysis of curves. Results of the fPCA highlighted 5 distinct time periods in the CoM curves that explained 91% of the variability in the data. These periods in which the young adults altered their CoM in response to visual field motion would not have been identified if we had relied on the onset and offset of the transient disturbance to distinguish responses. Young adults significantly displaced their CoM in response to visual motion over both the period of support surface tilt and while the support surface returned to a neutral position. Our results indicate that fPCA is a viable method when applied to the small but complex changes that emerge in postural data and might allow for a better understanding of time dependent processes occurring with pathology and intervention.
Authors:
Jill C Slaboda; Richard Lauer; Emily A Keshner
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, N.I.H., Extramural     Date:  2011-01-14
Journal Detail:
Title:  Neuroscience letters     Volume:  491     ISSN:  1872-7972     ISO Abbreviation:  Neurosci. Lett.     Publication Date:  2011 Mar 
Date Detail:
Created Date:  2011-02-21     Completed Date:  2011-07-05     Revised Date:  2012-03-21    
Medline Journal Info:
Nlm Unique ID:  7600130     Medline TA:  Neurosci Lett     Country:  Ireland    
Other Details:
Languages:  eng     Pagination:  138-42     Citation Subset:  IM    
Copyright Information:
Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Affiliation:
Physical Therapy Dept, College of Health Professions, Temple University, Philadelphia, PA 19140, USA. jslaboda@temple.edu
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MeSH Terms
Descriptor/Qualifier:
Adult
Female
Humans
Male
Postural Balance / physiology*
Posture / physiology
Principal Component Analysis / methods*
Proprioception / physiology
Rotation
Visual Fields / physiology
Young Adult
Grant Support
ID/Acronym/Agency:
AG26470/AG/NIA NIH HHS; DC05235/DC/NIDCD NIH HHS; R01 AG026470-04/AG/NIA NIH HHS; R01 DC005235-05/DC/NIDCD NIH HHS

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


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