Longitudinal changes in specific muscle strength but not in muscle anatomical cross-sectional areas is associated with change in knee function - data from the osteoarthritis initiative (OAI)

Abstract

Purpose: A positive and concurrent association between longitudinal change in knee function (worsening or improvement ≥6 [minimal clinically important difference (MCID)] on the WOMAC function score during Y2→Y4) and change in isometric extensor muscle strength was previously reported. Although muscle anatomical cross-sectional areas (ACSAs) or muscle mass have been shown to be moderately related to muscle strength, it is unknown whether function-related change in muscle strength depends on concordant change in ACSAs or specific strength (e.g.