Impact loading on the foot and ankle and its attenuation during level walking.

We studied impact loading on the foot and ankle at heel strike during level walking. Cadaveric testing was carried out on a skin-mounted accelerometer to estimate the bone or joint impact, and gait analysis was performed to evaluate the impact on the foot and ankle and its attenuation during level walking. Simulation using a rigid-body model estimated the impulse at landing during level walking. The skin-mounted accelerometer showed the same tendency as the bone-mounted accelerometer in cadaveric testing. In the gait analysis, impact at the calcaneus was attenuated at the medial malleolus and was less attenuated with the ankle fixation. In the simulation, impact became greater if the foot and ankle functions were eliminated. These results suggest that the foot and ankle are directly involved in attenuating the impact at heel strike during level walking.