Document Detail

End-state comfort and joint configuration variance during reaching.
MedLine Citation:
PMID:  23288326     Owner:  NLM     Status:  MEDLINE    
This study joined two approaches to motor control. The first approach comes from cognitive psychology and is based on the idea that goal postures and movements are chosen to satisfy task-specific constraints. The second approach comes from the principle of motor abundance and is based on the idea that control of apparently redundant systems is associated with the creation of multi-element synergies stabilizing important performance variables. The first approach has been tested by relying on psychophysical ratings of comfort. The second approach has been tested by estimating variance along different directions in the space of elemental variables such as joint postures. The two approaches were joined here. Standing subjects performed series of movements in which they brought a hand-held pointer to each of four targets oriented within a frontal plane, close to or far from the body. The subjects were asked to rate the comfort of the final postures, and the variance of their joint configurations during the steady state following pointing was quantified with respect to pointer endpoint position and pointer orientation. The subjects showed consistent patterns of comfort ratings among the targets, and all movements were characterized by multi-joint synergies stabilizing both pointer endpoint position and orientation. Contrary to what was expected, less comfortable postures had higher joint configuration variance than did more comfortable postures without major changes in the synergy indices. Multi-joint synergies stabilized the pointer position and orientation similarly across a range of comfortable/uncomfortable postures. The results are interpreted in terms conducive to the two theoretical frameworks underlying this work, one focusing on comfort ratings reflecting mean postures adopted for different targets and the other focusing on indices of joint configuration variance.
Stanislaw Solnik; Nemanja Pazin; Chase J Coelho; David A Rosenbaum; John P Scholz; Vladimir M Zatsiorsky; Mark L Latash
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2013-01-04
Journal Detail:
Title:  Experimental brain research     Volume:  225     ISSN:  1432-1106     ISO Abbreviation:  Exp Brain Res     Publication Date:  2013 Mar 
Date Detail:
Created Date:  2013-03-04     Completed Date:  2013-09-05     Revised Date:  2014-03-07    
Medline Journal Info:
Nlm Unique ID:  0043312     Medline TA:  Exp Brain Res     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  431-42     Citation Subset:  IM    
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MeSH Terms
Analysis of Variance
Biomechanical Phenomena
Hand Strength / physiology
Joints / innervation*
Movement / physiology*
Posture / physiology
Psychomotor Performance / physiology*
Young Adult
Grant Support

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

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