Enhance the stability of the knee joint is mainly to enhance the strength of the muscles around the knee joint as the goal of training, specific according to their own situation to choose the appropriate exercise. For example, lying on the bed for straight leg raising training, climbing stairs step training, squatting against the wall training. You can also ride a bicycle, which can exercise the muscle strength of the lower limbs, or you can choose to swim, lift dumbbells, do sit-ups, or use a variety of gym equipment for exercise. If the joint instability is caused by the postoperative period, it is important to train within the range of motion of the knee joint. Stability can be enhanced by training the muscles around the knee, with the quadriceps being the target, and this can be done gradually, step by step, from anti-gravity training to weight-bearing training. Regardless of which kind of training, it is necessary to step by step, step by step to strengthen the exercise, to find a suitable method for themselves, can not just seek success, increase the intensity, resulting in secondary injury. If the pain worsens or other discomfort occurs during the training process, it is important to go to a regular hospital in time for examination, follow the doctor’s advice, and exercise correctly.