Longitudinal change in functional performance measures prior and concurrent to clinically important worsening or improvement in womac knee function–data from the oai

Abstract

Purpose: Functional performance measures (FPMs) such as the Chair Stand Test [CST], 20-meter [m] and 400m Walk Test [WT] represent important tools in osteoarthritis (OA) research. Change in thigh muscle strength, but not in anatomical cross-sectional area has been reported to be predictive of longitudinal improvement in WOMAC knee function, but the predictive value of FPMs for change in WOMAC knee function has not been established yet. The purpose of the current work was to explore: 1) if change in FPM (CST, 20m- and 400m-WT) differs between the concurrent or preceding interval of WOMAC knee function worsening or improvement (exceeding the minimally clinically important difference); and 2) if FPMs differ between groups with worsening or improvement of WOMAC knee function when compared to a reference group without change in WOMAC knee function.