Model Analysis of the Human Foot Include Subtalar Joint, Taroclural Joint, and Foot Arch

The purpose of this study is to investigate the functional displacement of human foot complex during gait cycle. The methodlogy was to present the mathematical foot model which was three joints rigid rink 3 D model, consists of taroclural joint (TCJ), subtalar joint (STJ), and a foot arch as a single axis joint. And the angle motion and moments in each joints was determined using the inverse dynamics analysis method. The foot model parameter was sampled by anthropometric experimentation during a normal gait, and changed to the each joint coordinate system. The results of this study showed that the functional displacements of the three joints holding biomechanical relationships based on Elftman, and indicated the shape changes of the human foot complex during gait. We discussed that the muscle activities effect to the foot motion about the results of three joint moments in this 3 D model study.