Functional exercise after arthroscopy starts on the day of surgery and usually returns to the clinic for follow-up 4 weeks after surgery, why 4-6 weeks? Because at this stage the patient should be closely involved in rehabilitation. But unfortunately, this optimal time is basically spent by patients at home. Due to the lack of professional guidance, the fact that the patient is not a professional, and the influence of traditional Chinese culture that “it takes 100 days to break a bone”, most patients take a resting and basically immobile approach. After 4 weeks, there will be varying degrees of loss of mobility and joint adhesions in the limb joints at the time of follow-up, so this phase of follow-up will help correct the patient’s incorrect rehabilitation approach. Post-knee arthroscopy rehabilitation program Straight leg raise training: supine position, knee straight, raise the lower limb to 30°-45°, maintain for 10 seconds and then lower, repeatedly. Perform twice daily for 30-60 minutes each time. Patellar inward pushing activity: Fully straighten the knee joint, press the ipsilateral thumb against the lateral edge of the patella (kneecap), push the patella inward to the maximum and then release it, repeatedly. This is done twice daily for 15 minutes each time. Weight-bearing activities and knee extension and flexion activities can be performed when pain allows. However, do not forcibly extend and flex the knee joint with pain, as this may cause compression of the synovial membrane within the joint and aggravate synovial congestion and edema. In the second and third weeks after surgery, straight leg raising exercises should be performed twice a day for 30 minutes each time. On top of this, knee extension and flexion mobility training should be strengthened. Knee extension and flexion exercises may be slightly painful, but should be adhered to, with flexion reaching 90° by the third postoperative week. As the synovial inflammation subsides, the pain during mobility training will gradually decrease. The duration of extension and flexion exercises is 30 minutes twice daily. Further increases in knee flexion mobility are required from four weeks postoperatively, generally requiring knee flexion of more than 120° at 6 weeks postoperatively. This is done twice daily for 15 minutes each time. A leg press is also performed to ensure full extension of the knee. Replace supine straight leg raising with active knee extension in the seated position. Method: Sit on a stool or at the edge of the bed, drape the lower leg and then straighten it extremely, maintaining it at maximum extension for 10 seconds and then lowering it. At first, because the muscle strength has not recovered, it is not possible to straighten completely, and there will be some pain, but as long as you insist on exercising, you will gradually reach full straightness. Training time is 15 minutes twice a day. After being able to fully straighten easily, you can practice hanging weights on the ankle, starting with 1kg until you can hang 5kg weights on the ankle. Add weighted half-squats on the affected side with a range of 0°-45° (called 0° when the knee is fully extended). The method is: first fully straighten (0 °) standing, slowly flex the knee joint, squat to 45 °, in this position adhere to 5-10 seconds and then stand up, repeatedly. This is done twice daily for 15 minutes each time. At the beginning of the training because muscle strength has not recovered, single-leg support will become a problem, more difficult to maintain the knee at 45° for 5-10 seconds. You can start with a double-legged half-squat and then transition to a single-legged half-squat on the affected side. You can stand up immediately after starting a half squat, and then maintain a 45° half squat after muscle strength has been restored. Do not squat more than 45°, otherwise there is a risk of aggravating the injury.