Total knee arthroplasty is a highly effective procedure, but if the success of the surgery is based on the surgical technique without effective rehabilitation, the surgery will not be as effective as it should be. For total knee arthroplasty, functional exercise is as important as the surgery, as it relates to the future function and mobility of the knee. Under the guidance of a physician, functional exercises should begin as early as possible and should be based on active activities, supplemented by passive activities. It is normal to feel pain during the early activities, so you should not be afraid to move for fear of pain and lose the best practice period (within one week after surgery), which will affect the functional rehabilitation of the knee joint after surgery. Post-operative rehabilitation (exercise) guidance for total knee replacement includes: muscle strength training, gait correction, psychological adaptation and whole body training, etc. (1) Early exercise (0-7 days after surgery) The knee joint is in a slightly flexed functional position, and ice packs are applied externally within 24 hours. 6 hours after surgery, muscle functional exercises are started, such as quadriceps static contraction training [1], knee extension and elevation exercises [2], ankle extension and flexion exercises [3], etc.; the drainage tube is removed on the second and third days after surgery, and the venous lymphatic circulation therapy device of the lower extremity is performed to prevent venous thrombosis after the drainage tube is removed. On the third day after surgery, partial weight-bearing walking with the assistance of a walker was possible. (2) Mid-term exercise (8-14 days after surgery) Gradually increase the weight-bearing of the affected knee, but still crutches should be used for partial weight-bearing, and increase the sitting flexion exercises [4]. (3) Late exercise (15-21 days postoperatively) The focus is on gradually restoring the weight-bearing capacity of the affected limb, starting walking and gait training, and strengthening the patient’s balance training. Further strengthen the muscle strength enhancement training of the quadriceps and N cord muscles by using isotonic, isometric and isometric muscle strength training methods, and perform stair climbing training [5]. (4) Home exercise precautions ① Continue to do knee flexion, extension and muscle rehab exercises after going home; ② Keep the wound clean and dry, and shower four weeks after surgery, there will be numbness on the outside of the incision after surgery, which is normal; ③ In case of tooth extraction, cold or other diseases, the physician must be informed that the artificial knee joint has been replaced so that antibiotics can be given to prevent infection; ④ Generally, after surgery, do not put full weight on the affected limb for six weeks, and do not use crutches after three months. (5) After six months, you can swim, play golf and other mild sports, but avoid strenuous sports such as jumping, squatting, running, tennis, basketball, etc. (6) Please follow the doctor’s instructions and return to the clinic for regular checkups if you have any of the following conditions, such as redness, swelling, pain or abnormal pus discharge. (5) Walking Exercise Precautions Proper walking is the best way to help the knee joint recover, and it is necessary to start walking with the help of a walker or crutches. The first step is to feel comfortable and maintain balance while standing upright, then move the walker or crutches forward a small distance, straighten the knee on the operated side and move it forward, firstly follow the foot to the ground, move the body forward, then flatten the foot and finally release the toes from the ground. Walking frequency, pace distance and speed should be uniform, and when muscle strength and endurance are increased, the walking time can be gradually extended. (6) Notes on going up and down stairs Going up and down stairs requires strength and coordination, and is the best exercise to enhance the strength and endurance of the limbs, and requires help at first until sufficient strength and balance and coordination are regained. (7) General requirements for rehabilitation (exercise) The rehabilitation after total knee replacement should vary from person to person because the patient’s physical condition, medical condition, psychological quality, subjective requirements, and surgical procedure are different. In addition, since patients who receive total knee replacement have a history of long-term pain, deformity and dysfunction of the knee joint, functional exercise should be done gradually and not too quickly to avoid undue injury. [1] quadriceps static contraction training: patients lying down, lower limb straight, the affected limb do quadriceps static contraction dimension, hold for 5 seconds and then relax, 10 times as a group, four groups a day. [2] knee extension and elevation exercises: lower limb straight, as for quadriceps exercises, lift the leg off the bed a dozen centimeters, hold for 5-10 seconds, slowly put down, repeat this action until the thighs feel fatigue, three times a day. [3] Ankle extension and flexion exercises: the patient lies flat on the bed, the muscles are relaxed, keep the knee straight, and do 1 plantar flexion and dorsiflexion of the ankle joint at a uniform rate for 1 group, maintaining 8-10 groups per minute, doing 3-5 minutes each time, three times a day. 【4】Sitting flexion exercise: sit on a chair, put a towel under the joint, straighten the leg as much as possible, maintain the action, hold it for 5 seconds, then flex the knee as much as possible, maintain the action, hold it for another 5 seconds, keep repeating. 【5】Up and down stairs training: In the early stage, mainly rely on crutches and the lower limb of the healthy side to support up and down the stairs, the affected limb gradually transition from non-weight bearing to partial weight bearing, the healthy side goes up first and the affected side goes down first during training, after patients adapt to gradually reduce the dependence on crutches, and eventually be able to walk independently without crutches.