Abstract
The purpose of this study was to quantify the functional role of support leg joints including MP joint of the leg during running motion. The whole-body was modeled as a system of 16-rigid linked segments, and MP joint torque was estimated with sole pressure information. The equation of whole-body motion was derived considering constraint axes of joints such as inversion/eversion axes of the elbow and knee joints. The dynamic contributions of the support leg joint torques to the generation of whole-body CG's acceleration were calculated for two subjects with different foot contact pattern, such as rear-foot strike and fore-foot strike, under different running velocity conditions. The results in this study indicate that 1) planter/dorsal flexion torque of ankle joint is great contributor to the generation of horizontal and vertical components of body CG's acceleration, 2) abduction/adduction and internal/external rotation torques of hip joint contribute to the accelerations for rear-foot striker, and 3) planter/dorsal flexion torque of MP joint is small contributor and shows inverse pattern with respect to the contribution of planter/dorsal flexion torque of ankle joint.
