背景與目的：本研究的目的是從運動學與動力學的角度，分析慢性單獨後十字韌帶斷裂患者在行走時髖、膝、踝關節的動作型態與關節負荷，並比較患側與健側之差異。方法：受試者為7名單獨後十字韌帶斷裂超過3個月的患者，以健康的對側下肢為對照進行比較，受傷至參與研究的平均時間為1.5年，患側膝關節在日常生活中並無不適症狀，透過搭配6台紅外線攝影機的三維動作分析系統與2塊力板同步收集行走中下肢肢段的運動軌跡與地面反作用力，藉以計算動作過程中各關節角度與關節力矩的變化。所有運動學與動力學的參數均以魏可遜符號等級考驗進行患側與健側的比較。結果：在運動學方面，患側髖關節角度在著地初期屈曲角度較健側小(p<005)，在著地末期的伸直角度則比健側大(p<0.05)。患側膝關節的屈曲角度在著地初期後都明顯小於健側(p<0.05)，表示患側膝關節與髖關節相似，在著地期過程中都處於較伸直的狀態。兩側踝關節的角度則沒有顯著差異。另外，兩側平均步長的差異達到顯著(p<0.05)。在動力學方面，兩側的髖與踝關節力矩均沒有顯著差異，而膝關節力矩的差異發生於著地末期，患側的伸直力矩顯著的小於健側(p<0.05)。在地面反作用力方面，兩側並沒有顯著的差異，但由下肢支撐力矩的分佈顯示患側支撐力量有從膝關節轉移至踝關節的傾向。結論：後十字韌帶斷裂後無症狀患者在步態上出現適應情形，患側下肢的適應模式為著地期時髖關節伸直的角度增加與膝關節屈曲的角度減少，同時在著地末期膝關節的伸直力矩下降，且負荷期時出現以踝關節來代償膝關節伸直力矩的傾向。

Background and purposes: The gradual development of joint instability and eventual degenerative changes in the knee following posterior cruciate ligament (PCL) injuries has been noted. It is possible that individuals with PCL deficiency may change the movement patterns and external loads applied to the knee and maintain functional stability. There are few studies concerning evaluation of the biomechanical alterations of the lower extremity following PCL rupture. The purpose of this study was to identify differences in the joint angle and moment during walking between injured and uninjured limbs in individuals with chronic PCL rupture. Methods: Seven asymptomatic individuals with isolated PCL rupture were tested in regards to hip, knee, and ankle kinematics and kinetics while walking. The mean period between injury and testing was 1.5 years. Three- dimensional movement trajectories of lower limbs and ground reaction force were recorded using six infrared cameras and two force plates. The Wilcoxon signed-ranks test was used to compare kinematic and kinetic variables between injured and uninjured sides. Results: The hip joint angle of injured side showed less fiexion at initial contact and terminal stance (p<0.05). Similar findings were found in knee joint angle after initial contact (p<0.05). Stride length between injured and uninjured limbs also demonstrated a statistically significant difference (p<0.05). In kinetics, injured knee demonstrated smaller extension moment than the uninjured side, but those differences were only statistically significant (p<0.05) in the terminal stance. No significant difference was found in support moment among extremities at loading response, however, the ankle extensors generated larger moment to make up for the knee moment deficit. Conclusions: The main finding of this study is that asymptomatic individuals with chronic PCL rupture exhibited different gait patterns. This pattern of injured limb is characterized by the more extension in hip and knee joints during stance phase and reduced knee extension moment in the terminal stance.