Linked Life Data

12172665

Source:http://linkedlifedata.com/resource/pubmed/id/12172665

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-8-12
pubmed:abstractText
The central nervous system (CNS) must routinely compensate for unpredictable perturbations that occur during postural tasks. Such compensations could take the form of feedforward or feedback control. This study investigated whether the CNS, when faced with a potential postural perturbation, employs feedforward adjustments to reduce the near-term and overall likelihood of balance loss. Slips were induced, using bilateral low-friction platforms, during a sit-to-stand task in 60 safety-harnessed young adults. Subjects underwent a block of slipping trials, a block of nonslipping trials, then a mixed block of trials. After the first novel and unexpected slip, subjects were aware that a slip "may or may not occur." The state (horizontal position and velocity) of the body center of mass (COM) at seat-off and the direction of balance loss (forward, no loss, backward) were determined for each trial. Feedforward adjustments were identified as between-trial changes in COM state at seat-off. Effects of these adjustments on the likelihood of balance loss were quantified using logistic regression. Results indicated that the likelihood of balance loss in each direction (forward, backward) under each condition (slipping, nonslipping) was significantly related to the COM state at seat-off. When faced with the potential perturbation, the CNS made near-term feedforward adjustments to reduce the likelihood of balance loss under the conditions last experienced; exposure to slipping and nonslipping conditions resulted in adjustments that reduced the likelihood of backward and forward balance losses, respectively. Subjects adapted their performance over the longer-term in a manner that significantly decreased their overall likelihood of balance loss in either direction under either condition. The CNS thus adapted to acquire an "optimal" movement strategy that reduced the reliance on reactive responses to maintain balance in an uncertain environment.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
145
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
528-38
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Feedforward adaptations are used to compensate for a potential loss of balance.
pubmed:affiliation
Department of Physical Therapy (MC 898), University of Illinois at Chicago, 1919 West Taylor St., Fourth Floor, Chicago, IL 60612, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't