Distance-Induced Changes in Walking Speed After Stroke: Relationship to Community Walking Activity

Background and Purpose: Physical inactivity is a major contributing factor to reduced health and quality of life. The total distance walked during the 6-Minute Walk Test is a strong indicator of real-world walking activity after stroke. The purpose of this study was to determine whether measurement of distance-induced changes in walking speed during the 6-Minute Walk Test improves the test's ability to predict community walking activity. Methods: For 40 individuals poststroke, community walking activity (steps/d), the total distance walked during the 6-Minute Walk Test (6MWT(total)), and the difference between the distances walked during the final and first minutes of the test (Delta 6MWT(min6-min1)) were analyzed using moderated regression. Self-efficacy, assessed using the Activities-specific Balance Confidence scale, was also included in the model. Results: Alone, 6MWT(total) explained 41% of the variance in steps/d. The addition of Delta 6MWT(min6-min1) increased explanatory power by 29% (Delta R-2 = 0.29, P < 0.001). The final model accounted for 71% of steps/d variance (F-4,F-32 = 19.52, P < 0.001). Examination of a significant 6MWT(total) x Delta 6MWT(min6-min1) interaction revealed a positive relationship between 6MWT(total) and steps/d, with individuals whose distances declined from minute 1 to minute 6 by 0.10 m/s or more presenting with substantially fewer steps/d than those whose distances did not decline. Discussion and Conclusions: Coassessment of distance-induced changes in walking speed during the 6-Minute Walk Test and the total distance walked substantially improves the prediction of real-world walking activity after stroke. This study provides new insight into how walking ability after stroke can be characterized to reduce heterogeneity and advance personalized treatments.