前十字韌帶斷裂後，存在嚴重股四頭肌萎縮與自主活化能力不足的情形。以電刺激增加感覺輸入能有效增進股四頭肌的自主活化程度。本研究目的想探討增加感覺輸入的肌力訓練對前十字韌帶損傷者股四頭肌的自主活化程度與單腳落地動作表現的影響。19名自主活化程度低於90%的前十字韌帶損傷者隨機分成增加感覺輸入組與單純肌力訓練組，對受傷腳進行每次30分鐘，每週3次，共4週的等速肌力訓練。訓練前、後，兩組人均接受股四頭肌最大等長、自主活化與單腳落地測試。結果顯示，兩組人的等長肌力、自主活化程度、落地垂直地面反作用力皆顯著提升(p<.05)，落地後最大膝彎曲角度未顯著改變。4週的肌力訓練能有效改善前十字韌帶損傷者股四頭肌肌力、中樞驅動能力與傷側腳承重的能力，增加感覺輸入的訓練效果與單純肌力訓練相似。

Anterior cruciate ligament (ACL) ruptures often accompanied by severe quadriceps muscle atrophy and voluntary activation (VA) failure. It has been shown that additional enhanced sensory input (SI) with electrical stimulation (ES) could efficiently enhance the VA of the quadriceps muscle. The present study was aimed to investigate the effect of strength training with additional enhanced sensory input induced by ES on the voluntary activation, as well as the functional outcome in subjects with chronic ACL injury. Nineteen ACL injured subjects with VA below 90% were randomly divided into two groups: the strength training with additional SI group, and only the strength training (control) group. Isokinetic strength training program was conducted for three days per week, over a four weeks period. For the SI group, low intensity electrical stimulations were applied in the 30-minute strength training period. Maximum quadriceps isometric strength, voluntary activation, and single leg landings were performed before and after training. In the results, it was found that the maximum quadriceps strength, the VA and the maximal vertical ground reaction force were significantly (p<.05) increased after training in both groups. The maximum knee flexion angle after landing remains unchanged in both groups. The strength training program has been shown to efficiently improve the quadriceps muscle strength, the central drive and the ability to support the body weight. The effect of strength training with additional enhanced sensory input by ES was similar to that of strength training alone.