サッカーにおける第五中足骨疲労骨折に関する力学的評価指標の検討

抄録

Fifth metatarsal stress fracture occurs frequently in soccer. Many researches about occurring the injury have been conducted, however, they mainly focus on structure of feet or plantar pressure under fifth metatarsal bone. Therefore, the value and occurring mechanism of stress on the bone has not been clear. In this study, we conducted finite element analysis of movements in soccer using a foot finite element model and clarified stress at fracture position. Then, some mechanical parameters which have correlation with stress were found. Firstly, we conducted subjects experiments of 8 movements which occur frequently in soccer to define boundary conditions for finite element simulations. Foot motion, reaction force and plantar pressure distribution of 2 Subjects were measured in the experiments. After that, finite element analyses were conducted in cases of 3 movements, which are inside step, acceleration, cross step, by inputting measured data as boundary conditions for the foot finite element model. As a result of simulations, max principal stress at fracture area showed higher in acceleration case. However, considering duration time, the inside step case showed the highest value in 3 movements. In addition, it was found that each movement had different physical parameters which showed high correlation with stress at the fracture area; forefoot internal rotation, plantar pressure under fifth metatarsal bone or thenar.