Phase I (3 days after surgery) 1. Training of quadriceps: Place a towel rolled into a column under the thigh and use the towel as a fulcrum for knee flexion exercises under the effect of gravity. Use a larger towel to further increase the flexion angle of the knee joint. Keep the thigh muscle contraction state for 10 seconds, relax, repeat 10 times / group. 2. Ankle joint exercises: supine active maximum flexion and extension of the ankle joint and resistance training. The hemodynamic effect of ankle joint movement is significant and is one of the measures to prevent venous thrombosis. Each movement is held for 10 seconds and repeated 10 times/group. 3, hip muscle exercise: supine leg extension position, upper limbs comfortably placed on the side of the body, contract the hip muscles hold for 10 seconds, relax, hands forceful support, do hip lifting action and hold for 10 seconds, repeat 10 times / group. Low back pain is the most common symptom of many spinal disorders, which seriously affects human health and reduces patients’ quality of life. Approximately 40% of chronic low back pain in clinical practice is attributed to intervertebral disc lesions, and this paper reviews the recognition and treatment of discogenic low back pain in order to provide a reference for the current status of its research progress. Phase 2 (4-10 days after surgery) 1.Supine straight leg raising exercise: maintain from 15 seconds gradually increase, 10 times/group, 2~3 groups/day. 2.Supine hip flexion and knee flexion exercise: hold one hand under the knee and one hand on the heel, flex the hip and knee without causing abnormal pain. 10 times/group. 2~3 groups/day. 3.Knee flexion at the bedside: the hip joint of the affected limb is abducted, the foot is placed outside the bed, and the knee joint is flexed with force, so that the knee flexion gradually increases. 4.Supine knee extension: The patient lies on his back and places a pillow or pillar-shaped towel under the ipsilateral ankle joint. This gradually extends the knee joint with the gravity of the lower limb. If the knee extension is significantly limited, a sandbag should be pressed on the joint surface during early postoperative sleep at night. Phase III (2 to 3 weeks postoperatively) The aim of this phase is to strengthen the muscles and to maintain the acquired joint mobility. Mainly quadriceps resistance exercises: sitting on the bedside and extending the knee, the affected ankle plus sandbag to extend the calf, gradually increase from 1kg to 4 or 5kg, 50 times/return, 2 times/day. Notes】 1. It should be understood that the rehabilitation training of any joint is for two purposes: training of joint mobility and training of muscle strength around the joint. For the knee joint, joint mobility training should be the main focus in the early stage, and muscle strength recovery should be the main focus in the later stage. 2. The choice of intensity should vary from person to person, and the patient’s condition should increase the training content, but there should be minimum limits and requirements. 3.With no pain in the wound, walking on the ground with the help of crutches, weight-bearing options gradually increase, at the latest one month later can gradually fully weight-bearing.