Abstract
The foot joint has the great mechanisms. One of them is its arch structure. This makes bipedal locomotion possible. However, the mechanism is not elucidated, so engineering research is required. Experimental analysis by a photoelasticity method was done in this research. It targeted the normal foot and the flatfoot. The change in the height of an arch was investigated. All loads were static loading. The experiment model was a frame model without the tendons of a muscle. A pilot experiment of a 2-dimensional model was done. The cross-section of the inner side arch and the outside arch was made. It was divided into four by the bone positions. The simple stress distribution map of a foot arch was obtained. The 3-dimensional experiment was done with the result of two dimensions as reference. The 3-dimensional stress freezing method was used. All the bones of the foot joint were made separately. The stress distribution map showed some things. In a normal foot, the stress of a Calcaneus ground plane decreases outside. A flatfoot has much more stress concentration. Change in an arch influences the load distribution.
