Abstract
The purpose of this study is to investigate the influence of the heel-toe drop of shoe-sole on dynamic functional roles of the support leg muscles in running motion. Seven recreational runners participated in this study. Five types of shoes which have the different heel-toe drop of the soles were used. The muscle contributions of the support leg muscles to the body support and to the propulsion/braking of the whole body were derived from a dynamic analysis method based on the equation of the whole-body motion. The analysis showed the following results: the thicker shoe-sole in rearfoot to forefoot could produce, (1) the larger contribution of vasti to the support, (2) the smaller contributions of gastrocnemius and soleus to the support, (3) the larger contributions of soleus to prolusion and dorsiflexors to braking, respectively, and (4) the smaller contributions of gastrocnemius to the propulsion and vasti to the braking, respectively.
