本研究欲探討交替穿著不同鞋底硬度鞋，對下肢運動學的影響。受試者為13位男性跑者，受測鞋的鞋底硬度分為軟底(shore C45)及硬底(shore C70)兩種。受試者依硬軟硬及軟硬軟兩種不同穿著順序，在電動跑步機上完成規定時間的跑步，兩種組合分兩天進行。結果發現穿硬底鞋時，著地瞬間有較小的足跟著地速度，著地後有較大的膝、踝關節彎屈速度；交替穿著後，僅在穿著硬軟硬的組合中，著地後膝關節彎屈速度有過度調整的現象；步頻和步幅則未達顯著差異。由結果可知，跑者在跑步機上穿硬底鞋跑步時，會採用減小撞擊速度的著地策略，來降低撞擊能量以減緩與跑步機平台的衝擊力；而著地後，有較大的膝、踝關節彎屈速度，則可能與維持步態平衡有關。往後的研究應該注意到交替穿著不同鞋底硬度時，造成著地後膝關節彎屈速度過度調整的現象。本研究結果也發現，在探討跑步機上跑步的運動時， 應該注意著地後的下肢運動策略，而此策略是否有步態穩定有關，則需要更深入的研究來驗證。

The purpose of this study was to investigate the influences of alternately wearing soft and hard soled shoe on the lower extremity kinematics. Thirteen males were includes in this study to run on a motor driven treadmill with soft (shore 45C) and hard (shore 70C) soled shoes alternately. The results showed that the runners performed smaller heel impact velocity and greater knee and ankle flexion velocity after landing with the hard soled shoe. Over-tuning of knee flexion velocity after landing only occurred under the combination of wearing hard-soft-hard soles alternately. There were no any significant differences in stride frequency and length for wearing different hardness shoe. The results indicated that the runners adopted the landing strategy of smaller heel impact velocity, which leaded to a less impact energy, to reduce the impact forces as striking. The greater knee and ankle flexion velocity after landing seemed to keep the support leg stability at the stance phase. In the future, the over-tuning of knee flexion velocity after landing under alternately wearing hard-soft-hard soles and the support leg movements at the stance phase during treadmill running should be noticed.