Abstract
The purpose of this study was to study the effect of impact velocities on the passive impact forces of the whole foot and heel part during rear foot strike running. Three healthy male subjects performed three sets of barefoot running at self-selected normal, slow, and fast speeds to get running data. A simple mechanical model consisting of two masses, linear springs, and dampers and nonlinear spring which could consider contact phases of running and contact points: the heel and toe parts was used to simulate vertical ground reaction forces. Sensitivity analysis was done by changing impact velocities. The results showed that the peak passive impact forces of the whole foot and the toe part had a different tendency. Furthermore, the average vertical loading rates of the toe part ground reaction were higher than those of the whole foot ground reaction force in spite of their similar tendency.
