Ambulation of people with lower-limb amputations: relationship between capacity and performance measures.

OBJECTIVES: To examine the relationship between measures of ambulation capacity obtained in a clinical setting and measures of ambulation performance in the community, and to explore what demographic and clinical variables influence ambulation performance in people with lower-limb amputations.

DESIGN: A cross-sectional, correlational and descriptive study.

SETTING: Rehabilitation center and participants' homes and community environments.

PARTICIPANTS: Community-dwelling people (N=52) with lower-limb amputations at the unilateral transfemoral (n=16), unilateral transtibial (n=30), and bilateral transtibial (n=6) levels. All had been fit with prostheses for over 1 year.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Measures of ambulation capacity were the Locomotor Capabilities Index version 5, the 2-Minute Walk Test (2MWT), and the Timed Up and Go Test. Measures of ambulation performance included a commercially available step activity monitor (SAM; steps per day, minutes active per day, peak activity index) and self-reported performance with the Activity Restriction subscales of the Trinity Amputation and Prosthesis Experience Scales (TAPES).

RESULTS: Most relationships among capacity and performance measures were in the moderate to high range (Spearman correlation coefficients, rho=.41-.78, P<.05). The highest correlation coefficient was between the 2MWT and SAM peak activity index (rho=.78, P=.000). A multivariate analysis found the 2MWT was significantly related to increased performance as measured by SAM mean steps per day (P=.026) and TAPES (P=.016). Depressive symptoms were also a significant predictor (P=.003) of decreased performance (TAPES).

CONCLUSIONS: The 2MWT, a measure of ambulation capacity, correlates well with most SAM measures of ambulation performance. Exploratory regression analysis indicated that the 2MWT is related to ambulation performance, while depression is only related to self-reported performance.