Article

Parkinson's disease (PD) causes instability and difficulty adapting to changing
environmental and task demands. We examined the effects of PD on the adaptation
of gait termination (GT) on a slippery surface under unexpected and cued
circumstances. An unexpected slip perturbation during GT was followed by a slip
perturbation during GT under two conditions: planned over multiple steps and cued
one step prior to GT. Feed forward and feedback-based responses to the
perturbation were compared to determine (1) how PD affects the ability to
integrate adaptive feed forward and feedback-based GT strategies on a slippery
surface, (2) if adaptations can be implemented when GT is required within one
step, and (3) if behaviour changes with repeated exposure. Similar to the control
group (n=10), the PD group (n=8) adapted and integrated feed forward and
feedback-based components of GT under both stop conditions. Feed forward
adaptations included a shorter, wider step, and appropriate stability margin
modifications. Feedback-based adaptations included a longer, wider subsequent
step. When cued to stop quickly, both groups maintained most of these
adaptations: foot angle at contact increased in the first cued stop but adapted
with practice. The group with PD differed in their ability to adapt GT with
slower, wider steps and less stability.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS