I. 1 to 3 days after surgery Let the patient know about the exercises, the core of which is to improve the muscle strength of the affected limb. This is very important for the patient. The recovery of postoperative muscle strength is beneficial to postoperative rehabilitation and early activity, and also helps to reduce bedside complications, especially the incidence of deep vein thrombosis in the lower limbs. 1.Ankle pump exercise: This exercise can be done in bed from the day after surgery. When doing this exercise, an intravenous pain pump can be applied to control the pain of the incision. Patients force the knee joint straight, ankle joint dorsiflexion, and then try to contract the thigh and calf muscles at least 6 times, and then relax completely. This allows the quadriceps to contract isometrically to prevent muscle atrophy, as well as rotating the ankle joint and moving the toes at will, which promotes blood return. The exercises should be performed in groups of 5 to 10 times each, 3 to 6 groups per day. Each action should be done as much as possible, from slow to fast. 2, leg compression exercises: on the second day after surgery, patients can sit up and practice pressing the knee joint, especially in patients with flexion contracture deformity before surgery. Place the leg straight on the bed, use a soft pad at the heel, and place your hands above the knee and gently press down to straighten the leg as much as possible, maintaining about 5 minutes each time until the patient is in intolerable pain, which is the best way to exercise straightening. Knee straightening after artificial knee replacement is much more difficult than flexion, and equally important, only straighten the leg to walk normally without causing pain through. 3. Prevention of edema: The affected limb can be elevated with a special lower limb pad to facilitate blood return, and the distal end of the affected limb should be above the level of the heart, while the proximal end (thigh) is slightly below the level of the heart. The knee joint should be flexed 5° to 10° to prevent common peroneal nerve palsy, and the ankle joint should be dorsiflexed 90° with the heel suspended to prevent pressure. After the operation, the vital signs and blood seepage from the incision should be closely observed, gently massage the quadriceps and gastrocnemius muscles for the patient, adjust the comfortable position, reduce the patient’s pain caused by anesthesia and lower limb braking, and massage away from the knee joint without touching the wound. 4. Psychological guidance: Patients often have anxious and irritable psychology after surgery due to incisional pain, rejecting medical staff and failing to cooperate well with the rehabilitator. When performing early rehabilitation exercises, the nurse should pay attention to the patient’s psychological reaction, and give patient guidance and affirmation to every movement of the patient with encouraging words, so that the patient can establish self-confidence and practice consciously. Understand the patient’s rehabilitation exercises daily, such as the degree of joint mobility and straight leg elevation, and make a suitable rehabilitation plan together with the patient. Work well with the patient’s family so that they can actively participate in the patient’s rehabilitation exercises to facilitate the continuation of rehabilitation exercises after discharge. Organize communication and mutual introduction of exercise feelings and experiences among patients to improve the exercise effect. The patient’s attitude toward the disease and life will directly affect the patient’s willingness to recover and the attitude to cooperate with medical and nursing staff. Therefore, only according to patients’ different psychological conditions and social backgrounds can we provide patients with realistic rehabilitation guidance. Second, 3 to 14 days after surgery 1. Exercise without pain: On the third day after surgery, remove the drainage tube and take X-ray to review the position of the prosthesis before practicing straight leg raising, patients should exercise without pain, teach patients the method of straight leg raising, the height should not be higher than 30cm, every 5 or 10 groups, 3 to 5 groups per day. The method is to first force the back of the foot to hook upward, then force the leg to straighten, then raise the whole leg, maintain it for a few seconds and then put the leg down and relax completely. Exercises should be performed in groups. The intensity of exercise should start from small intensity, and gradually transition and maintain small and medium intensity as the condition recovers, and the judgment standard is based on the patient’s subjective perception. 2.Passive exercise: On the third day after surgery, if the patient’s general condition is good, the patient can carry out passive exercises for hip and knee flexion with the help of a continuous passive exercise device. The initial practice of flexion and extension starts from 0-30°, after that the number of flexion increases by 10° every day, and should reach 120° two weeks after surgery, twice a day, 30 minutes each time, the frequency is from slow to fast, the range of activity is based on the patient’s pain-free range, and the patient’s recovery should be taken into account. When the patient feels pain, it means that the range is too large, at this time, the speed of recovery should not be pursued, keep the previous angle exercise for 2 days, and then increase incrementally. CPM has a good effect on the recovery of muscle strength and the recovery of hip and knee mobility, it helps the patient to start the passive activities early, thus preventing the adhesion of the tissues around the joint, making the joint movement improve, promoting the functional recovery and enhancing the ligament strength to meet the daily life It helps the patient to start the passive activities as early as possible, so as to prevent the adhesion of the tissues around the joint, improve the joint activities, promote the functional rehabilitation, and strengthen the ligaments to meet the daily needs. 3.Leg bending exercise: start the exercise from the 3rd day after surgery. At the beginning, it can be done on the side of the bed, the patient sits on the side of the bed and relaxes naturally, the leg hangs under the bed by gravity, it can reach 90°, then use the good leg to the front, help to press the affected limb backward, you can increase the angle of knee flexion, the size of the force to be able to tolerate, if you can maintain the force for a few minutes, the effect is better. 4. Active knee flexion and extension activities: start practicing on the 3rd day after surgery. When the quadriceps and gastrocnemius muscle strength is recovered to a certain extent and the postoperative pain is mild, use CPM exercises at the same time. 5. Knee exercises when extension lag and flexion limitation: used when the knee cannot be fully straightened or flexed to 90° 2 weeks after surgery. Generally, when the extension lag of the affected knee exceeds 5° to 10° and the flexion is less than 75° to 90° at 9 to 10 days after surgery, we can start to correct the knee with manual thrusting under anesthesia and supervision, so that the knee can be passively straightened and flexed to more than 90°. After that, rest for 1 day and restart the above exercise on the 2nd day. 3. 2 weeks after surgery 1. Standing exercises on the gait rack: rely on the gait rack for standing exercises to prepare for further standing and walking. When standing, the patient’s subjective perception is the main factor in the transition to standing of the affected limb due to the instability of the affected limb joints and relatively weak muscle strength. 2. Gait training of the exercise frame: hold the handle with both hands, stand with the body standing, look ahead, move the exercise frame forward first, then move the healthy leg, then move the affected leg. 3. Double axillary cane three-point walk: Patients need help when they first get off the ground. Three-point gait, is a fast moving gait. It is suitable for patients who have normal function of one lower limb and cannot use the other side when it is unable to bear weight, and who have a strong upper arm. When walking with double crutches, the two axillary crutches are synchronized with the affected limb and alternate with the healthy side. At the beginning of each 10-20 minutes, 2 times / day, and then gradually increased to two 20-30 minutes, 3 or 4 times a day. When using crutches should be hand-held weight, crutches axillary cross handle should be kept at a distance of two fingers from the armpit, can not use the armpit to hold the weight, so as to avoid nerves and blood vessels under the armpit is crushed.