For many patients who have undergone surgery for joint disorders (after knee replacement, meniscus injury, cruciate ligament injury), there is always apprehension and confusion about how to perform effective rehabilitation. The following are some common post-operative rehabilitation methods for the lower extremities: 1. In the supine position, tense the upper thigh muscles and press the knee joint down toward the bed. 6 seconds/time, 10 times/group. 2.Under the supine position, raise the straight leg 30 degrees, maintain it for 10 seconds, relax and rest for 10 seconds. Sandbags can be gradually used for training. 3. Side lying, hip abduction exercises, maintain 10 seconds, relax and rest for 10 seconds. Can gradually use sandbags for training. 4. Side lying position, hip abduction exercises, can gradually use the sandbag for training. The following diagram shows: 5, under the thigh pillow so that the knee joint flexion of about 30 °, and then actively extend the knee, reach the highest point to maintain 10 seconds, relax and rest for 10 seconds. You can gradually use sandbags for training. Or knee extension exercises in sitting position. 6.In the supine position, press the bed with the heel as shown, but keep the whole lower limb immobile. 6 seconds/time, 10 times/group. 7.Bend the knee exercise to the maximum and stay for 10 seconds.