Exercises for repairing knee injuries should be chosen appropriately under the guidance of a doctor. For knee injuries caused by trauma, after the acute phase, you can carry out knee mobility training and stability training-based exercises. 1. Knee mobility training (1) Passive movement, the patient lies on his back, the therapist is located on the affected side, holding the affected ankle below and the knee above, and lifting the affected limb to make it in the position of hip flexion and knee flexion, and the affected limb will be flexed through the front of the body in the range of joint activity close to the abdomen, and restoring it to its original position will be knee extension. (2) Assisted or active exercise, the patient lies supine, the lower limbs are naturally straightened, and the knee flexion and extension exercises are done under the assistance or initiative, alternating between the right and left lower limbs. You can also flex the hip at 90 degrees in the sitting position and do knee flexion and extension. The exercise should be done gradually and without obvious pain. 2. Stability training (1) knee flexion and extension resistance exercise training prone position, fixed elastic band at the ankle joint of the affected limb, do flexion and extension resistance exercise; you can also sit down, ankle weight (sandbags) and other flexion and extension exercises. (2) squatting against the wall: upright upper body close to the wall, do squatting, thighs parallel to the ground and calves into 90 degrees, 1 minute for 1 group, can do 5 groups. For degenerative knee injuries caused by aging, you can properly participate in weight reduction exercises, such as cycling, swimming, etc., to reduce the load of weight on the knee joint at the same time, you can strengthen the muscles and ligaments around the knee joint stability. It is recommended that patients with knee injuries, standardized treatment and training under the guidance of a doctor, so as not to cause secondary injuries, so as not to miss the condition.