Mohsen Sadeghimehr - Dept. of mechanics Bu-Ali Sina University Hamadan, Iran
Zohreh Salimi - Dept. of mechanics Bu-Ali Sina University Hamadan, Iran
Mina Karami - Dept. of mechanics Bu-Ali Sina University Hamadan, Iran

The purpose of this paper is persenting a multisagment static model of the foot, in order to find muscle forces of the leg and foot in miscellaneous posture of gait. To obtain an ecact knowledge about magnitude and location of forces in various parts of the foot, a more precise foot model is needed. In the present study, a four segment musculoskeletal model of foot (hallux, forefoot and himdfoot plus one segment for tibia) is usedto assess the foot druing gait. Input parameters of the model are relative angles between different segments of the model and grund rection forces on the fist metatarsl and hee. Then< the main muscles are added to the model, and Newton equations of equilibrium are applied to study the invers dynamic of the problem. Since several muscles act in foot motion, the unmber of unkown parameters in the equations is qreater than the unmber of known ones. Therefore, with the aim of optimizing Euclidean norm of muscle forces, an optimal solution for the problem is found.

muscle force, normal foot, musculo-skeletal model, stance