本研究的主要目的在分析赤腳與穿鞋跑時著地初期的力學特性。四位男性受試者在赤腳與穿鞋跑兩種情況下，測量地面反作用力及下肢運動學參數，跑步速度控制在3m/sec。研究結果，赤腳跑時撞擊力峰值較早發生，且最大負荷率明顯大於穿鞋跑。赤腳跑著地瞬間膝關節較穿鞋跑時彎曲，膝關節彎曲角速率較大，小腿與地面的夾角較接近90°，足底與地面的夾角較小，足跟的水準速度較小，顯示受試者於赤腳跑時為因應不同的足－鞋底表面性質而調整其著地策略，其目的應在降低足底的壓力，及降低撞擊的能量以減小撞擊負荷。本研究中雖然受試者赤腳跑時會調整著地的策略，以降低與地面的撞擊能量，但因足跟皮脂的快速壓縮變形下造成其勁度升高，因而產生較大的最大負荷率。

The purpose of this study was to investigate the mechanical characteristics during the initial stance phase in barefoot and shod running. The vertical ground reaction forces and sagittal plane kinematics of four male subjects running barefoot and shod were detected at the speed of 3m/sec. Barefoot running showed a significantly larger maximum loading rate and more early impact force peak than shod running during the initial stance phase. In barefoot running, the larger knee flexion and angular velocity, more vertical position of the shank, flatter foot placement and smaller horizontal heel velocity at the landing instant were the adaptation strategies of the subjects to reduce the plantar pressure under the heel and the impact loading. Impact energy and stiffness of the foot-shoe-ground system were suggested to affect the maximum loading rate. In this study, the subjects landed with lower horizontal heel velocities to reduce the impact energies in barefoot running, however, the larger maximum loading rate was found because of the larger stiffness of the heel pad.