 |
| Research article summary (published 30 Jul 2003): |
|
Free Full Text! See links below |
Role of feedforward control of movement stability in reducing slip-related balance loss and falls among older adults.
Full Abstract
Human upright posture is inherently unstable. To counter the mechanical effect of a large-scale perturbation such as a slip, the CNS can make adaptive adjustments in advance to improve the stability of the body center-of-mass (COM) state (i.e., its velocity and position). Such feedforward control relies on an accurate internal representation of stability limits, which must be a function of anatomical, physiological, and environmental constraints and thus should be computationally deducible based on physical laws of motion. We combined an empirical approach with mathematical modeling to verify the hypothesis that an adaptive improvement in feedforward control of COM stability correlated with a subsequent reduction in balance loss. Forty-one older adults experienced a slip during a sit-to-stand task in a block of slip trials, followed by a block of nonslip trials and a re-slip trial. Their feedforward control of COM stability was quantified as the shortest distance between its state measured at seat-off (slip onset) and the mathematically predicted feasible stability region boundary. With adaptation to repeated slips, older adults were able to exponentially reduce their incidence of falls and backward balance loss, attributable significantly to their improvement in feedforward control of stability. With exposure to slip and nonslip conditions, subjects began to select "optimal" movements that improved stability under both conditions, reducing the reliance on prior knowledge of forthcoming perturbations. These results can be fully accounted for when we assume that an internal representation of the COM stability limits guides the adaptive improvements in the feedforward control of stability.
Learn Faster Today Improve your study skills
Author information
Author/s: Pai, Y-C (YC); Wening, J D (JD); Runtz, E F (EF); Iqbal, K (K); Pavol, M J (MJ);
Affiliation: Department of Physical Therapy, University of Illinois at Chicago, 60612, USA. cpai@uic.edu
Grants: R01AG-16727 (Agency:United States NIA)
Journal and publication information
Publication Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.
Journal: Journal of neurophysiology (J Neurophysiol), published in United States. (Language: eng)
Reference: 2003-Aug; vol 90 (issue 2) : pp 755-62
Dates: Created 2003/08/07; Completed 2003/10/01; Revised 2007/11/14;
PMID: 12904492, status: MEDLINE (last retrieval date: 11/6/2008)
Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.
External Links for this article (including full text providers, if available):
Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.
This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.
MeSH headings (categories)
This article was linked to the MESH Headings shown below.
|
|
Related articles
This article has not been indexed for related articles as yet, however you can still use the live related article search links below.
See a large map of 100+ related articles.