Abstract
Recently, the number of foot joint syndromes by an acquired transformation increases. Because loading condition and the structure of foot joint greatly influence them, the clarification of the mechanical property of foot joint is important. Especially, a flatfoot has a lot of patients as an acquired case. In this research, the bone in the arch of a normal foot and a flat foot was reproduced by three-dimensional model, the stress distribution was analyzed by the photoelastic investigation, and it made comparative study of them. The experiment analysis result showed the following things. The remarkable difference was seen by calcaneus. In ground plane, stress concentration caused the normal foot inside. Stress decreased as the normal foot went outside. On the whole, stress increased the flatfoot. And, reduction of the stress in an outside like a normal foot was not seen.
