Article

Gait variability measures have been linked to fall risk in older adults. However,
challenging walking tasks may be required to elucidate increases in variability
that arise from subtle age-related changes in cognitive processing and
sensorimotor function. Hence, the study objective was to investigate the effects
of visual perturbations, increased cognitive load, and narrowed step width on
gait variability in healthy old and young adults.
Eleven old (OA, 71.2+/-4.2
years) and twelve young (YA, 23.6+/-3.9 years) adults walked on a treadmill while
watching a speed-matched virtual hallway. Subjects walked: (1) normally, (2) with
mediolateral visual perturbations, (3) while performing a cognitive task (serial
seven subtractions), and (4) with narrowed step width. We computed the mean and
variability of step width (SW and SWV, respectively) and length (SL, SLV) over
one 3-min trial per condition. Walking normally, old and young adults exhibited
similar SWV and SLV. Visual perturbations significantly increased gait
variability in old adults (by more than 100% for both SWV and SLV), but not young
adults. The cognitive task and walking with narrowed step width did not show any
effect on SWV or SLV in either group. The dramatic increase in step width
variability when old adults were subjected to mediolateral visual perturbations
was likely due to increased reliance on visual feedback for assessing whole-body
position. Further work is needed to ascertain whether these findings may reflect
sub-clinical balance deficits that could contribute to the increased fall risk
seen with advancing age.
CI - Copyright (c) 2015 Elsevier B.V. All rights reserved.

Langue : ANGLAIS