Abstract
The purpose of this study was to quantify the functional role of compressive characteristics of shoes sole by combining a finite-truss-element shoe model and equation of whole-body motion. The equation of the shoe sole deformation was developed by modeling sole as a construction of truss elements with nonlinear spring and damper properties. The coefficients of the properties were identified from impact test by using an impact device consisting of accelerometer and arm with an impactor. The equation of whole-body motion was derived by modeling the human body as a system of 15-rigid linked segments with consideration of DOF in joint constraint axes and of changes in lengths of modeled segments. Dynamic contributions of the support leg joint torques, which were caused by the elastic and viscous property of the shoes sole, to the generation of whole-body CG' s acceleration were calculated under constant running speed conditions. The results in this study indicate that 1) the plantar flexion torque about the ankle caused by the elastic property of the forepart of shoes sole contributes to the horizontal and vertical acceleration of whole-body's CG, and 2) the extension torque of the knee caused by the elastic property of shoe sole contributes to the horizontal deceleration and the vertical acceleration of whole-body CG.
