The effect of cane use on the compensatory step following posterior perturbations

Objective. The compensatory step is a critical component of the balance response and is impaired in older fallers. The purpose of this research was to examine whether utilization of a cane modified the compensatory step response following external posterior perturbations. Design. Single subject withdrawal design was employed. Single subject statistical analysis––the standard deviation bandwidth-method––supplemented visual analysis of the data. Methods. Four older adults (range: 73–83 years) with balance impairment who habitually use a cane completed this study. Subjects received a series of sudden backward pulls that were large enough to elicit compensatory stepping. We examined the following variables both with and without cane use: timing of cane loading relative to step initiation and center of mass acceleration, stability margin, center of mass excursion and velocity, step length and width. Results. No participant loaded the cane prior to initiation of the first compensatory step. There was no effect of cane use on the stability margin, nor was there an effect of cane use on center of mass excursion or velocity, or step length or width. Conclusions. These data suggest that cane use does not necessarily improve balance recovery following an external posterior perturbation when the individual is forced to rely on compensatory stepping. Instead these data suggest that the strongest factor in modifying step characteristics is experience with the perturbation.