Effect of Motion Type on Joint Contact Forces

Race walking has grown over the past decade because it provides exercise without the high impact loads of running. In fact, race walking has been shown to result in decreased ground reaction forces. We predict these lower ground reaction forces will extend to knee joint loading as well, thus explaining the decrease rate of knee osteoarthritis in race walkers compared to runners. This is a secondary analysis of instrumented motion capture data collected from fifteen competitive race walkers as they ran and race walked over a force plate. A Visual3D to OpenSim pipeline was used to create muscle actuated forward dynamics simulations of race walking and running. The resulting muscle forces were subsequently used to actuate a discrete element knee model to calculate joint forces. The peak tibiofemoral joint contact load during race walking was 18% lower than the load during running. This load was distributed between the medial and lateral compartments such that the medial load was 27% lower and the lateral load 35% lower in race walking. This suggests race walking is a lower impact exercise safer for the joints. This may be advantageous for people who would like to exercise at a higher intensity that walking provides but have joint problems, e.g. those with osteoarthritis.