下肢勁度 (Lower extremity stiffness) 是運動生物力學在探討表現或傷害時常見的一個關鍵因 素，然而諸多研究證實下肢勁度對運動表現與傷害的相關影響，但對於勁度測量方法仍有些許混淆不 清以及誤用的情況產生。本文主要針對垂直、腿部與關節勁度進行計算方法與參數使用上的釐清，進 一步探討勁度與運動表現的關係。對於運動表現或傷害的情況而言，勁度已確認具有一定程度上的影 響力。因此，確立勁度計算方法與參數獲得技術將有助於評估勁度對於運動員的影響，建議教練員了 解關節勁度較能反應下肢各關節的真實情況，垂直勁度適合較為單一的動作型態，腿部勁度則也可以 比較動態運動過程的勁度表現，進而提供運動員作各式訓練動作上的安排與參考。

Lower extremity stiffness is an important factor in sport biomechanics research for performance and injury. However, many studies have proved that stiffness may be related to performance and injury, but still some researches inconsistencies stiffness measurement or misuse exists. The aim of this study was to clarify the measurement of vertical, leg and joint stiffness model, and further investigation the relationship between stiffness and injury. Stiffness had proved that it will affect sport performance and injury risk. Thus, establish measurement methods and data collection techniques were important for identified the influence of stiffness for athletes. We suggest that coach should understand joint stiffness was better reflect the real situation, vertical stiffness is more suitable for single action patterns, leg stiffness is also possible to compare the performance of the dynamic movement. Thereby provide training schedule of athletes.