Article

Compensatory steps are essential for preventing falls following perturbations.
This study aimed to explore age-related changes in compensatory steps to
unilateral perturbations, specifically in terms of whether anticipatory postural
adjustments (APAs) play a role in stabilizing lateral balance. Five young and
five elderly male adults participated. The split-belt treadmill was used to
provide bi- and unilateral perturbations, as forward or backward transitions,
applied 10 times in random order. Backward steps evoked by unilateral forward
perturbations were evaluated. We measured temporal characteristics, mediolateral
(ML) center of mass (COM) motion, and ML step length of compensatory steps.
Compensatory steps to unexpected perturbations showed delayed onset of foot-off
(FO) and expanded lateral swing length in elderly compared to young subjects.
Differences in COM motions and step width arose related to APAs. Elderly subjects
showing APAs exhibited no significant differences in ML COM, ML COM velocity, or
ML swing length compared to young subjects. However, elderly subjects without
APAs showed significant changes toward instability in these parameters. The fact
that APAs play a notable role, particularly in the elderly, in stability offers a
new insight into preventing falls. However, APAs occurred in 29% of the steps of
young and 35% of the steps of elderly subjects. If the occurrence of APAs in
elderly people in response to compensatory steps was more frequent, fall risk
would be reduced. Further studies, particularly into APA frequency, might
contribute to improved intervention to prevent falls.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS