Article

Postural instability is a major risk factor of falling in the elderly. It is well
documented that postural control may decline while performing a concurrent
cognitive task and this effect increases with age. Despite the extensive use of
dual tasking in balance assessment protocols, a lack of sufficient reliability
information is evident. This study determines the reliability of the postural
stability measures in older adults, assessed under single and dual-task
conditions and different levels of postural difficulty. Sixteen older adults
completed quiet stance postural measurements at three levels of difficulty (rigid
surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed), with
or without performing a concurrent backward counting task, in two sessions 1 week
apart. Force plate data was used to calculate center of pressure (COP) parameters
including mean velocity, phase plane portrait, area (95% confidence ellipse),
standard deviation (SD) of amplitude, and SD of velocity. Intraclass correlation
coefficient (ICC), standard error of measurement (SEM), coefficient of variation
(CV), and minimal metrically detectable change (MMDC) were calculated for each
COP measure in all test conditions. Mean velocity, total phase plane, phase plane
in ML direction, and SD of velocity in ML direction were the most reliable COP
measures across all test conditions. ICC values were consistently higher in ML
direction compared with AP direction. In general, velocity-related COP measures
in ML direction showed to be highly reliable. Further research may explore the
predictive and evaluative value of these COP parameters.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS