Six-minute walk test in persons with transtibial amputation.

OBJECTIVE

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.

DESIGN

Test-retest study design.

SETTING

University research laboratory.

PARTICIPANTS

Subjects (N=13) with transtibial amputation (9 men and 4 women; mean age, 46 y).

INTERVENTIONS

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.

MAIN OUTCOME MEASURES

(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.

RESULTS

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).

CONCLUSIONS

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.