運動員下肢受傷的復健過程，除了以肌力、肌耐力等參數來作為評估的依據外，也常以下肢與地面接觸的訊息來做為評量的參考依據。本文根據一般下肢受傷者的特點，如受傷腳著地時的地面反作用力會比非受傷腳之著地地面反作用力小，達成左、右下肢地面反作用力的不相稱等特性，模擬一下肢受傷之模型。這些特性包括走路時的第一峰值、第二峰值、單足支撐時間、負荷率及接觸地面時間的左右相稱值等五個變數，然後，以測力跑步機，測量42位下肢受傷者及19位未受傷者有關此五個變數的足底訊息，並套入模擬之下肢受傷模型，進行模式之評估。 結果顯示左、右下肢受傷者的五個變數之相稱值均無法套入預設之模式中，本研究測試的下肢受傷對象中有15位是左下肢受傷，27位是右下肢受傷，而受傷之部位也有所差異，分佈在踝關節、膝關節及肌肉拉傷等，因此，本研究懷疑是否這些不同受傷部位可能造成足底訊息的特性無法一致，而另一可能是本研究將所有個人之左、右足的足底訊息之變數值全部以平均值代表，這或許亦有可能使受傷的特性消失，也有可能因擷取資訊時間太短，步伐的型態尚未明顯表示出來，而左、右慣用腳在本研究中並未事先列入考慮，或許也是缺失原因之一。這些都是未來研究可進行的方向，如延長擷取資訊之時間，再利用時域分析法來觀察下肢受傷者與非受傷者是否在步伐上有特殊的型態出現，而建立一正常人之步態常模也是非常重要的。

Muscle strength, endurance were often used for the evaluation of the rehabilitation program in lower extremity injury. However, the symmetry index (SI) is as one of the methods to evaluate gait pattern in lower extremities, helps to determine symmetry in the kinetic data between injured and un-injured lower extremities. In this study, we proposed two injury models using gait parameters. Gait data were then used to test these two models. These data were collected from 42 injured subjects and 19 un-injured subjects using treadmill that equipped with two force plates. In the models, we assumed that the symmetry value would shift to un-injured side for the first peak value, second peak value, weight acceptance rate and single limb stance time, and would stay at injured side for contact time. However, our data failed to prove this assumption and concluded that gait symmetry for injured lower extremity is unpredictable. From this study, we suggested that more data from normal subjects is needed in order to develop a norm data for gait pattern, and injured region of lower extremity might be a fact that influenced our data analysis, so as dominant leg which may affect gait symmetry, all of these need to be studied in future investigation. Furthermore, longer data acquisition may be also needed, so that the method of time domain analysis or frequency domain analysis may be applied to find out gait pattern for injured and un-injured subjects.