The 2-minute walk test as a measure of functional improvement in persons with lower limb amputation

Objective: To determine the construct validity and responsiveness of the 2-minute walk test as a measure of function in individuals with lower extremity amputation. Design: The distances walked in 2 minutes were compared with the results on the physical functioning subscale of the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-36) and the Houghton Scale. Setting: Regional amputee rehabilitation program. Patients: Retrospective data from 290 patients (mean age, 66yr) With unilateral transtibial, unilateral transfemoral, or bilateral amputations. Intervention: Repeated testing. Main Outcome Measures: Distance walked in 2 minutes, SF-36 (aggregated into physical and mental composite scores), and the Houghton score. We also examined the change in the distance before and after a rehabilitation program. Results: The distance walked in 2 minutes showed a weak correlation with the physical functioning subscale of the SF-36 (r = .22, p = .008) and a moderate correlation with the total Houghton score at discharge from rehabilitation (r = .493, p less than or equal to .001). The correlation between distance walked in 2 minutes and SF-36 physical functioning subscale at follow-up was moderate (r = .479, p < .001). There was a significant improvement in distance walked in 2 minutes at discharge and follow-up compared With baseline (mean change standard deviation at discharge, 13.6 +/- 19.9m; at follow-up, 41.2 +/- 34m, p < .001). Conclusion: The 2-minute walk test was responsive to change with rehabilitation in persons with lower extremity amputation. In addition, the 2-minute walk test showed adequate correlation with measures of physical functioning and prosthetic use in this population.