EMG-Driven inverse dynamic analysis of knee contact forces during gait and cycling using OpenSim

Joint contact forces determine the loading experienced by cartilage tissue and, thus, may be used to predict risk of cartilage tissue damage and osteoarthritis (OA). Participating in low impact and/or non-weight bearing activities such as cycling may help reduce knee OA risk by limiting forces exerted during exercise [1]. Cycling is a common recommendation for rehabilitative or fitness sustainment exercise for select patients [1]. Although knee joint contact forces have been directly measured in gait and cycling using instrumented knee implants [2,3] and calculated in gait using EMG-driven analysis [4]; they have not been calculated in cycling using EMG-driven analysis. The long-term goal of this study is to identify weight control exercises for overweight (OW) and obese (OB) subjects that minimize OA risk. This current study tests the hypothesis that knee joint contact forces are significantly lower during cycling than gait. The objectives are to: (1) conduct motion analysis experiments and EMG-driven OpenSim analyses for gait and cycling, (2) compare predicted tibiofemoral (TF) contact forces to published values, and (3) test for significant differences in maximum TF compressive forces in gait and cycling