Compensatory stepping responses in individuals with stroke: A pilot study

Abstract

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.

ACKNOWLEDGMENTS

The authors thank Luke Johnston, Gerald Sung, and Tasneem Taherali for their assistance with data collection and processing. This study was supported by the personnel awards from the Natural Sciences and Engineering Research Council of Canada (BL), and the Heart and Stroke Foundation Centre for Stroke Recovery, the Heart and Stoke Foundation of Canada, the Canadian Institutes of Health Research, and the Canadian Stroke Network (AM). We also acknowledge the support of the Toronto Rehabilitation Institute who receives funding under the Provincial Rehabilitation Research Program from the Ministry of Health and Long Term Care in Ontario.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.