Article

Impaired postural control and a high incidence of falls are commonly observed
following stroke. Compensatory stepping responses are critical to reactive
balance control. We hypothesize that, following a stroke, individuals with
unilateral limb dyscontrol will be faced with the unique challenge of controlling
such rapid stepping reactions that may eventually be linked to the high rate of
falling. The objectives of this exploratory pilot study were to investigate
compensatory stepping in individuals poststroke with regard to: (1) choice of
initial stepping limb (paretic or non-paretic); (2) step characteristics; and (3)
differences in step characteristics when the initial step is taken with the
paretic vs. the non-paretic limb. Four subjects following stroke (38-165 days
post) and 11 healthy young adults were recruited.
Anterior and posterior
perturbations were delivered by using a weight drop system. Force plates recorded
centre-of-pressure excursion prior to the onset of stepping and step timing. Of
the four subjects, three only attempted to step with their non-paretic limb and
one stepped with either limb. Time to foot-off was generally slow, whereas step
onset time and swing time were comparable to healthy controls. Two of the four
subjects executed multistep responses in every trial, and attempts to force
stepping with the paretic limb were unsuccessful in three of the four subjects.
Despite high clinical balance scores, these individuals with stroke demonstrated
impaired compensatory stepping responses, suggesting that current clinical
evaluations might not accurately reflect reactive balance control in this population.

Langue : ANGLAIS