前十字韌帶重建後能否返回運動場上的關鍵因素為下肢肌肉力量與動態姿勢穩定的控制能力，而下肢神經肌肉控制能力對於前十字韌帶重建者在著地階段扮演重要角色，因此，重建後的運動員需經歷一個標準化的復健與物理治療程序，並以功能性的評估來檢查膝關節是否具備正常的功能。常見的功能性測試包括開眼與閉眼平衡、折返跑、交叉步、單腳直膝跳與躍起著地等動作測試，而躍起著地動作為經常用於測量下肢動態穩定能力的功能性動作之一。目的：本研究主要目的係探討前十字韌帶重建後運動員在執行躍起著地動作時的下肢關節運動與肌肉活化特徵。方法：以9名前十字韌帶重建後運動員為重建組 (年齡22.5 ± 0.8歲；身高170.3 ± 8.5公分；體重65.7 ± 11.3公斤；術後時間23.3 ± 16.8月)，另外招募9名與其性別、年齡、身高、體重與運動項目配對為對照組，進行躍起後單腳著地平衡的測驗；利用十台Vicon紅外線攝影機 (200 Hz) 和8枚無線肌電電極 (1000 Hz) 同步收集生物力學參數；使用無母數分析比較重建組與對照組的差異。結果：重建組臀中肌與股直肌的肌肉預收縮RMS-EMG活化高於對照組，其數值分別為5.3% 與3.2%。重建組在著地瞬間會運用較多的膝關節屈曲，以較為屈曲的方式著地；著地後膝關節活動範圍小且關節運動時間短；推蹬期的腓腸肌與脛前肌RMS-EMG活化高於對照組，其數值分別為1.7% 與8.3%。結論：重建組著地前以臀中肌與股直肌的肌肉預收縮作為著地瞬間髖與膝關節的穩定機制；在著地瞬間以膝關節較多屈曲的方式著地並縮短關節運動時間降低不穩定狀態；推蹬期以腓腸肌與脛前肌作為穩定踝關節的重要策略。

Purpose: An important factor in postoperative rehabilitation and return to play decision making is to ensure appropriate restoration of lower extremity muscular strength and dynamic postural control. We can know the anterior cruciate ligament reconstruction of lower limb neuromuscular control for the individual plays an important role during landing period. Therefore, the athletes after ACLR need to have standardized rehabilitation and physical therapy program, as to functional assessment, as looking over whether the knee joint possesses the normal function. The common functional test its include eyes open, eyes closed, shuttle run, crossover step, one-legged hop and jump landing. The jump landing is commonly used to measure dynamic stability of the lower extremity. The aim of this study was to investigate the characteristics of lower extremity kinematics and muscle activations in athletes after anterior cruciate ligament reconstruction during jumping-landing maneuver. Methods: Nine participants with a history of unilateral anterior cruciate ligament reconstruction (22.5 ± 0.8 year, 170.3 ± 8.5 cm, 65.7 ± 11.3 kg; Time since surgery: 23.3 ± 16.8 months) and nine sex, age, weight, height and sport matched participants who served as the control group were recruited for this study. Participants were asked to perform a double­leg jump followed with a single­leg landing. Ten Vicon infrared video cameras (200 Hz), and eight wireless EMG sensors (1000 Hz) were synchronized to acquire the lower extremity 3D kinematic data and muscle activation profiles during jump landing. Nonparametric test (Mann-Whitney U test) was used to compare ACLR and control group (α = .05). Results: During pre-landing phase, the ACLR group showed significantly greater gluteus medius and rectus femoris muscle pre-activation, and greater knee flexion angle compared to the control. The ACLR group demonstrated a significant less movement time then the control group during the descending phase of landing. During propulsion phase, greater gastrocnemius and tibialis anterior muscle activations were found compared to the control group. Conclusions: When performing jump-landing protocol, the ACLR group utilized more gluteus medius and rectus femoris muscle to maintain hip and knee stability during landing period. In addition, greater knee flexion angles and less movement time were adopted by the ACLR group to enhance joint stability during the decending phase. Gastrocnemius and tibialis anterior muscles were activated as the landing strategy to help stabilize the ankle.