Muscle contributions to the tibiofemoral joint contact force during running - biomed 2010.

Running is typically performed at faster speeds than walking, and requires more muscular efforts. Because muscle forces substantially influence joint forces, the tibiofemoral (TF) joint force developed during the stance phase of running is expected to be greater than the force during walking. However, little is known about how individual muscles affect the TF joint force. Such information could be valuable for developing preventive or rehabilitation guidelines for knee joint injuries/diseases including cartilage damage and osteoarthritis that may be associated with high joint loading. Therefore, this study was aimed at identifying individual muscle contributions to the TF joint force during running. Muscle contributions to the axial TF joint force (the force component parallel to the longitudinal axis of the tibia) were computed using a muscle-actuated forward dynamic simulation of running at 2.4 m/s. Using a ground reaction force decomposition technique [1], individual muscle contributions to ground reaction forces were first obtained. Then, only the muscle force of interest and corresponding ground reaction forces were applied to the dynamic system, and resultant axial TF joint force was computed. The simulation showed that the primary contributor to the joint force from early to mid-stance was the quadriceps. From mid- to late stance, the gastrocnemius and the hamstrings contributed to the joint force. To a lesser extent, muscles that do not cross the knee joint (the gluteus maximus and the soleus) also contributed to the TF joint force through their contributions to ground reaction forces.