Wheelchair propulsion test: development and measurement properties of a new test for manual wheelchair users.

OBJECTIVE To develop and assess some of the measurement properties of a simple and inexpensive test that can be used to evaluate the wheelchair mobility of manual wheelchair users. DESIGN The initial phase of the study was developmental and descriptive. For the assessment of reliability and validity, correlations and comparisons were carried out using within-participant and subgroup comparisons. SETTING Rehabilitation center. PARTICIPANTS Manual wheelchair users (N=58), a sample of convenience. INTERVENTION The Wheelchair Propulsion Test (WPT) consists of wheeling 10m while time is recorded with a stopwatch, and the number of cycles and propulsion methods are recorded by observation. The WPT was administered once to each participant. Participants in subgroups involved in the assessment of reliability, construct, and concurrent validity had an additional WPT on the same occasion. MAIN OUTCOME MEASURES Derived measures-speed (m/s), push frequency (cycles per second) and effectiveness (meters per cycle)-from the WPT and, for concurrent validity, an instrumented rear wheel. RESULTS Regarding intra- and interrater reliability, intraclass correlation coefficients ranged from .72 to .96. Content validity was qualitatively good. For construct validity, on univariate or multivariate analyses, we found statistically significant relations between WPT measures and age, sex, duration of wheelchair use, type of wheelchair frame, and rolling surface. For concurrent validity, the WPT and instrumented wheel variables were highly correlated (r range, .92-.99), and there were no clinically significant differences between them. CONCLUSIONS The WPT appears to be a simple and inexpensive test with good measurement properties that can be used for people who use hand and/or foot propulsion. However, further study is needed before widespread implementation can be recommended.