Six-minute walk test in persons with transtibial amputation.

Abstract

This study was to report the within-day test-retest reliability and the measurement properties of the six-minute walk test (6MWT) in persons with lower-limb (transtibial) amputation. Test-retest study design. University research laboratory. Subjects (N=13) with transtibial amputation (9 men and 4 women; mean age, 46 y). Three trials of the 6MWT were conducted within 1 day with 20 to 30 minutes of rest between consecutive trials. Timed Up & Go (TUG) test and timed one-leg balance tests were conducted on another day. (1) Distance, heart rate, symptoms and signs of exercise intolerance during the walk test, (2) times of the TUG test and the one-leg balance test. The intraclass correlation coefficient (ICC3,1) value was .94. Bland and Altman graphs showed no systemic variations between trials and a small learning effect. The peak heart rate approximated 72% to 78% of the age-predicted maximal heart rate. Moderate degrees of correlation were observed in: (1) the 6MWT versus the TUG test (r=-.76, P<.05), and (2) the 6MWT versus the timed prosthetic-leg stance (with eyes open: r=.63, P<.05; with eyes closed: r=.61, P<.05). These findings suggest that the 6MWT could be considered as a reliable measure of functional capacity, involves a moderate degree of exercise intensity, and is related in a moderate degree to postural control abilities in persons with transtibial amputation.