Artificial total knee arthroplasty is a kind of surgery with very definite efficacy. If we only put the success of the surgery on the surgical technique but do not carry out effective rehabilitation training, we can not achieve the desired effect of the surgery. For knee replacement, functional exercises play an equally important role as surgery, which is related to the function and mobility of the knee joint in the future. Under the doctor’s guidance, the earlier the functional exercise starts, the better. Functional exercises should focus on active activities, supplemented by passive activities. It is as important, if not more important, to practice straightening and flexing the knee. It is normal to feel pain during early activities, and it is important not to be afraid of pain, so as to lose the best period for practicing activities (within one week after the operation), which will affect the function of the knee joint. The purpose of postoperative rehabilitation is to restore the function of the patient’s limbs and the ability of self-care through early functional training. Ankle pump action: foot and ankle extension and flexion activities can be started after awakening from anesthesia, 2 to 3 minutes each time, 2 to 3 times per hour. Quadriceps exercises: On the second postoperative day, start quadriceps exercises to maintain muscle tone. Try your best to dorsiflex the ankle joint, straighten the knee joint to do leg lifting for 5 seconds, relax for 5 seconds and then repeat until the thigh muscles feel fatigued. Knee lifting exercises: straighten the lower limbs, as for quadriceps exercises, lift the leg away from the bed for more than ten centimeters, maintain 5 to 10 seconds, slowly put it down, repeat this action until the thighs feel fatigue. You can also do the straight leg elevation exercise in the sitting position, by contracting the thigh muscles, make the knee straight and keep it for 5 to 10 seconds. Knee extension exercises: lie on your back, put a small pillow on top of the heel so that the heel is suspended in the air, contract the thigh muscles, so that the knee is completely straight, and try to make the back of the knee contact with the mattress, maintain 10 to 15 seconds, repeat this action until the thigh muscles feel fatigue. Heel Slip Flexion Exercise: Start after the drain is removed. Lie on your back, make the sole of the foot slide on the bed towards the buttocks, at the same time make the knee flex to the maximum, and hold it in this position for 5 to 10 seconds, repeat this many times until the leg feels fatigue. Sitting-assisted knee flexion exercises: After getting off the floor, sit on the side of the bed or chair and slowly bend the knee joint to its maximum extent. Then move one side of the foot to the back of the other side of the foot, the use of gravity pressure to make the knee again as far as possible flexion, and maintain 5 to 10 seconds, repeat until the leg feels fatigue. Early activities on the ground On the second to fifth day after surgery, you can go down to the ground and practice standing under the doctor’s guidance. On the third to fourth day after surgery, after the postoperative inflammatory reaction subsides, you can begin to do short-distance walking exercises. These early exercises help to regain muscle strength around the knee, improve joint mobility and restore balance and coordination. Walking Exercises Proper walking is the best way to help your knee recover, and you will need to start walking with a walker or crutches. First of all, you should feel comfortable and be able to maintain balance when standing upright, then move the walker or crutches forward for a small distance, straighten the knee on the operative side and move forward, first make the foot follow the ground, move the body forward, then flatten the foot, and finally the toes leave the ground. Walking frequency, pace distance and speed should be even. When the muscle strength and endurance have increased, you can gradually extend the walking time. Walking up and down stairs Walking up and down stairs requires strength and coordination, and is the best exercise to enhance body strength and endurance, which needs to be helped at the beginning until sufficient strength and balance and coordination are regained. Post-operative rehabilitation after total knee replacement should be individualized due to the patient’s physique, condition, psychological quality, subjective requirements, and surgical procedure. In addition, since patients who have received total knee replacement have a history of long-term pain, deformity and dysfunction of the knee joint, the functional exercise should be based on the principle of gradual and orderly progress, and should not be rushed to avoid undue damage. Each patient should be guided by the supervising physician, and the opinion of the attending physician should be the highest instruction.