Determine real change in performance during single session of functional testing

OBJECTIVE: Performance-based measures of function are used in both clinical and research settings. During functional testing procedures, participants’ performance change from one trial to another. Therefore, there is a need to know how much change in performance is considered a real change from one trial to another during the same testing visit. METHODS: The current study has a cross-sectional design. A sample of 51 healthy subjects participated in this investigation. Participants attended 1 testing visit during which all subjects completed the functional tests twice. The functional tests used in the current study were: timed up and go, 10-meter walking time, 5 times chair rise, and climbing stairs. RESULTS: Intra-class correlation coefficients were high on all functional tests for the whole sample and for different subgroups of age and gender. There were small standard error of measurement (SEM) and MDC values for the whole sample on all functional performance tests. Age groups showed different SEM and MDC on the repeated performance of tests. However, gender didn’t have an effect on SEM and MDC. CONCLUSIONS: The current study provides data that can guide clinicians in determining whether trial-to-trial changes in performance would be real changes or just measurement error.