Step Test Scores Are Related to Measures of Activity and Participation in the First 6 Months After Stroke

Background. The Step Test (ST) is a measure of dynamic standing balance and paretic-lower-extremity motor control in patients with stroke. Little is known about the extent to which impairments assessed by the ST relate to activity and participation during stroke recovery. Objective. The purpose of this study was to determine relationships between ST scores and measures of activity and participation during the first 6 months after stroke. Design. This was a prospective cohort study. Methods. Thirty-three individuals (18 men, 15 women) with a diagnosis of a single, unilateral stroke participated in the study. Participants were tested one time per month from 1 to 6 months poststroke. The ST was considered an impairment-level measure. Self-selected gait speed and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) Physical Function Index (PFI) were used to assess physical function. Three domains (mobility, basic and instrumental activities of daily living, participation) of the Stroke Impact Scale were used to assess self-reported disability. Regression analyses were conducted to examine the bivariate associations between ST scores and each physical function and disability measure at each time point (1-6 months). Results. The ST scores were positively associated with both physical function measures. The associations were stronger for self-selected gait speeds (R-2 = .60-.79) than for the PFI scores (R-2=.32-.60). During the first 6 months after stroke, each additional step with the paretic lower extremity oil the ST corresponded to a 0.07-m/s to 0.09-m/s increase in gait speed, and each additional step with the nonparetic lower extremity was associated with a 0.07-m/s to 0.08-m/s gait speed increase. The impairment-disability associations were weaker than the impairment-physical function associations. Limitations. Limitations Of the study include a relatively small sample size and lack of examiner blinding with regard to participant characteristics. Conclusions. Impairments in balance and paretic-lower-extremity motor control, as measured by the ST, relate to physical function and disability during the first 6 months following stroke.