This program should be implemented under the guidance of an orthopedic surgeon. Since each patient’s condition is different, the specific rehabilitation exercises should be carried out in conjunction with the patient’s specific situation to develop a suitable and individualized rehabilitation program. A removable or hinged brace should be worn for 4-6 weeks after ACL reconstruction. In addition to knee rehabilitation, active activities of the adjacent joints can be started as early as possible. Pain will exist during rehabilitation exercises and is unavoidable. If the pain diminishes or disappears within half an hour of exercise cessation, there is generally no tissue damage and rehabilitation can continue. Muscle strength exercises should be performed throughout the rehabilitation program. Each exercise should be performed until the muscles feel sore and fatigued, and then the next set should be performed after sufficient rest. Improvement in muscle strength is a key factor in restoring joint stability and should be maintained. The swelling of the knee joint will accompany the entire exercise process until the knee flexion and extension angles and muscle strength return to normal, then the knee swelling will gradually subside. If there is a sudden increase in knee swelling, the exercises should be adjusted and the amount of activity should be reduced, and the patient should return to the hospital for a review if necessary. Immediately after functional exercise, ice should be applied for 15-20 minutes. If you usually feel swelling, pain and heat in the joint, you can continue to apply ice 2~3 times a day. Phase I: Within 1 week after surgery Brace requirements: Knee brace locked in 0 degree extension position. You can walk on the ground with the help of double crutches, and the affected limb is not weight-bearing. Functional exercise: 1. Ankle joint active flexion and extension exercise (ankle pump): the full range of plantar flexion and dorsiflexion activities of the ankle joint can promote blood circulation and eliminate swelling, which is important to prevent the emergence of deep vein thrombosis in the lower limbs. Once a day for 2 hours, 1~2 sets of 20 sets each time. 2.Straight leg raise training: after extending the knee, keep the knee joint straight, raise it to the heel leaving the bed at 10~15 cm, keep it for 30~60 seconds/time. Exercise 3 sets per day, 20~30 times per set. 3. Knee mobility exercise: The affected knee is required to be able to passively straighten to 0 degrees and flex the knee at an angle of less than 90 degrees. The following methods can be used, the principle of exercise is passive closed chain knee flexion exercise. Supine closed-chain knee flexion exercise: requires that the heel of the foot does not leave the bed during knee flexion and moves on the bed surface, called “closed-chain”. This can be replaced by sliding the foot along the wall, or by sitting in a chair with the affected side of the foot assisting in the knee flexion exercise. Knee flexion and extension exercises can be performed using CPM (continuous passive knee mobilization). This is done twice daily for 20-30 minutes. Phase 2: 2~3 weeks after surgery 1. Continue the above exercises Add prone knee flexion exercises; 2. CAM training; 3. Terminal knee extension muscle strength exercises: knee extension strength exercises in the range of knee joint near extension (0~20 degrees), 4 times daily, 1~2 sets of 20 each, with 2 minutes rest between sets. 4.Resistance ankle plantar flexion training: against external resistance, toe force downward. 5.Knee mobility forging: passive knee flexion 0~100 degrees, active knee flexion 0~80 degrees. 6.Foot sliding along the wall training. 7.Standing position: straight leg raise training, hook leg training. Fourth week functional exercise 1, patellar loosening; 2, passive knee flexion and extension mobility: 0~105 degrees, active mobility: 0~90 degrees; 3, can be prone position knee flexion, standing position knee flexion exercise; 4, muscle strength training: (1) straight leg raise: can resistance, resistance from 0.5 pounds (or 250 grams) gradually increased to 5 pounds (2.5 kg) (2) hip joint abduction, adduction, posterior extension Resistance training: resistance gradually increased from 0.5 lbs (250 g) to 5 lbs (2.5 kg) (3) Micro-squat training (0~30 degrees), each lasting 30 seconds, 20 repetitions per set, 3 sets per day. Postoperative 5-6 weeks exercise program 1.Knee mobility training: passive knee mobility: 0~125 degrees, active mobility: 0~105 degrees; 2.N rope muscle resistance training: resistance flexion of the knee joint; 3.Weight-bearing and balance training: partial weight-bearing training of the affected limb in the parallel bar (50%~100%), left-right and front-back weight transfer training; 4.front-back and side-to-side stride training; 5.Unicycle Walking training Power bicycle training 15 minutes postoperative 13 weeks to 14 weeks gradually transition to adaptability and flexibility training.