The affected limb should not be weight-bearing for four weeks after meniscus body injury suture and no flexion exercises (passive knee flexion is not done either) for one week after surgery, and no active flexion exercises for four weeks. I. Protection period (1 day to 4 weeks after surgery) The day after surgery and the day after surgery Immediately after surgery, apply pressure bandage, elevate the affected limb, and fix it with a straight splint. After the anesthesia subsides, start to try: 1. Ankle pump – forcefully, slowly, full range of flexion and extension of the ankle joint, as much as possible. After getting off the ground, ankle pump exercises under anti-gravity can be performed. 2. Quadriceps (anterior lateral thigh muscle group) isometric contraction exercises – i.e. thigh muscle tensing and relaxation. Do as many as possible without increasing pain. (Greater than 500 times / day) 3, N rope muscle (posterior thigh muscle group) isometric contraction exercises – the affected leg force down the padded pillow, so that the posterior thigh muscle tensing and relaxation. Requirements as above, greater than 500 times / day. (2) Two days after surgery: 1.Start to try straight leg lift – straight leg lift after knee extension until the heel is 15cm from the bed, hold until exhaustion. 10 times/group, 2-3 groups/day. 2.Start leg raising exercises in all directions, 30 times/group, 2-4 groups/day, with 30 seconds rest between groups. (iii) 1 week after surgery: 1. Continue and strengthen the above strength exercises. 2.Passive knee flexion to 90 degrees. (D) 2-4 weeks postoperatively: 1. Continue and strengthen the above strength exercises. 2. Start multi-angle isometric resistance knee extension exercises to strengthen the leg. 30 reps/set with 30 seconds rest between sets, 4 sets in a row, 2-3 times/day. 3 Increase passive knee flexion angle by about 10 degrees per week. (v) 4 weeks after surgery: 1. Intensive strength exercises. 2.Passive knee flexion to 120 degrees. 3.Active knee flexion to 90 degrees. 4.Start to practice rotation of the lower leg, range until just natural stop. 5. Begin partial weight-bearing with a load of approximately one-third to one-half of body weight. Second, resume the weight-bearing period (5-7 weeks after surgery) This period should not be too much walking, otherwise it is very easy to cause joint swelling and fluid accumulation, affecting the functional recovery and tissue healing. 1. Gradually increase the weight-bearing of the affected limb, and gradually put on full weight 6 weeks after surgery. Weight-bearing and balance exercises – separate both feet under protection, move the center of gravity alternately from side to side within the range of slight pain, gradually transition to full weight-bearing standing on one leg, 5 minutes/time, 2-3 times/day. Separate both feet anteriorly and posteriorly, move the center of gravity, and gradually transition to full weight-bearing standing on one leg. 2. 5-7 weeks after surgery, continue to perform passive knee flexion exercises with the help of the surgeon, but maintain the passive angle at 120 degrees. 3, Flexion and extension knee 0-30 degree strength exercises, 30 reps/set, 2-4 sets/day, 30 seconds rest between sets. 4.Flexion and extension knee 30 degree half squat, 2 minutes / time, rest 5 seconds, 10 consecutive times for 1 group, 2-3 times / day. (For those with patellofemoral joint symptoms, perform straight leg raise and 20 degrees-0 degrees open chain knee extension training.) Third, the recovery period (8-12 weeks after surgery) 1. 8 weeks after surgery, the affected limb can be fully weight-bearing. 2.Passive knee flexion of more than 120 degrees and active knee movement exercises at 8 weeks after surgery. 3.In order to strengthen the posterior thigh muscle group, start “hook leg” static exercises, bend to a painless angle and hold for 10-15 seconds, 10 times/group, 4 groups/day. 4.Start the front-back and side-to-side straddle exercise, 20 times/group, 4 groups/day. 5.Fixed bicycle exercises, no load to light load. 10-20 min/set, 2 sets/day. 6.Athletes can start the training of basic technical movements of special sports three months after surgery. But must be gradual! Knee pads can be worn for protection if necessary, but are only recommended for use during strenuous exercise. 4. Recovery period (after 3 months) 1. Gradually resume strenuous activities or special training. 2. Strengthen muscle strength and joint stability during running and jumping. 3. If the muscle strength of the affected side reaches 85% or more of that of the healthy side, and there is no pain and no obvious swelling during the exercise, then the exercise can be fully resumed.