Calcaneal loading during walking and running

Purpose: This study of the foot uses experimentally measured kinematic and kinetic data with a numerical model to evaluate in vivo calcaneal stresses during walking and running. Methods: External ground reaction forces (GRF) and kinematic data were measured during walking and running using cineradio graphy and force plate measurements. A contact-coupled finite element model of the foot was developed to assess the forces acting on the calcaneus dur ing gait. Results: We found that the calculated force-time profiles of the joint contact, ligament, and Achilles tendon forces varied with the time-hi story curve of the moment about the ankle joint. The model predicted peak t alocalcaneal and calcaneocuboid joint loads of 5.4 and 4.2 body weights (BW ) during walking and 11.1 and 7.9 BW during running. The maximum predicted Achilles tendon forces were 3.9 and 7.7 BW for walking and running. Conclus ions: Large magnitude forces and calcaneal stresses are generated late in t he stance phase, with maximum loads occurring at similar to 70% of the stan ce phase during walking and at similar to 60% of the stance phase during ru nning, for the gait velocities analyzed. The trajectories of the principal stresses, during both walking and running, corresponded to each other and q ualitatively to the calcaneal trabecular architecture.