I. Passive exercises 1. CPM-assisted exercises: CPM-assisted exercises for knee flexion and extension, from small to large angles, progressively. 2. Extension-assisted exercises: For those with knee flexion contracture, extension exercises are very important. The heel can be padded and the gravity of the lower extremity can be used to help straighten the knee joint. Apply auxiliary pressure if necessary. Weight-bearing and walking exercises 1. Weight-bearing walking: The duration of weight-bearing varies from surgery to surgery. Most knee arthroscopy can be weight bearing early after surgery. For special surgeries such as meniscal sutures and subchondral bone drilling, weight bearing is not possible for a short period of time or not at all, so abduction or walking aids are needed. Gradually increase the weight-bearing until normal. 2, half squat exercise: hold a sturdy chair or bed frame, feet from the chair or bed frame about 20 cm. Slowly bend the knee joint down squat. Do not squat completely, and not more than 90 degrees. Hold for 5-10 seconds, slowly stand up straight and relax. Repeat 10 times.