Article

The study tested the hypothesis that vestibular patients (n=14) with chronic
unsteadiness caused by a documented peripheral unilateral vestibular dysfunction
would display differences in muscular activation and movement pattern during gait
initiation compared to age-, gender- and body-size-matched healthy Controls
(n=14). The displacements of the whole body Center of Pressure (CoP) during the
preparatory phase before the swing leg is lifted, were markedly different in
vestibular patients. The backward shift during this phase was significantly
smaller than in Controls, coupled with a larger secondary corrective forward
shift of the CoP. Conversely, the CoP-shift in the M-L direction towards the
stance leg was larger in the vestibular patients. Most vestibular patients lacked
the anticipatory tibialis anterior (TA) burst, which normally is a prerequisite
for the backward displacement of the CoP that precedes the forward movement. The
vestibular patients displayed more pronounced TA-Gastrocnemius coactivation in
the stance leg when the swing leg was lifted. The duration of the preparatory
phase was significantly longer in vestibular patients than in Controls, with no
time differences in the later gait initiation events. The vestibular patients
started from a more symmetrical stance and with less M-L variation than the
Controls. It is concluded that chronically impaired vestibular function leads to
a different strategy to create forward momentum to the body. In addition, there
is evidence that vestibular patients have diminished postural stability, or
alternatively a more cautious behaviour, when initiating the second step.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS