The replacement of a diseased joint with an artificial prosthesis for various reasons is called joint replacement. These procedures are becoming increasingly popular, with hip and knee replacements being the mainstay. Post-operative rehabilitation is an important part of the success of an artificial joint, but the percentage of people who receive reasonable rehabilitation is not high. It is said that the reason why the joints do not become wormy is because of the movement. If a joint does not move after surgery, adhesions and contractures can occur, causing pain and destroying the joint’s function. The hip and knee joints are weight-bearing joints, and because they cannot bear weight immediately after surgery, patients will choose to be bedridden. Prolonged bed rest can bring harm to various body systems: decreased cardiopulmonary function, poor digestion, osteoporosis, muscle atrophy, etc. In addition, a series of post-operative complications, such as deep vein thrombosis, crushing pneumonia, and bed sores, are also closely related to post-operative inactivity. The joint is “sensory”, while the artificial prosthesis is inanimate. Without proper post-operative training, the sense of position and movement of the joint is diminished, and the ability to move, including balance, is diminished. In turn, inappropriate post-operative exercise can result in loosening or dislocation of the prosthesis, making the surgery a lost cause. Inappropriate exercise later in life can reduce the life of the prosthesis. Reasonable post-arthroplasty rehabilitation is necessary to avoid the hazards of braking and to reduce the consequences of inappropriate exercise. It can be done programmatically, but with minor adjustments depending on each individual’s situation. In general, “post-operative” rehabilitation can begin before surgery, when the patient learns breathing exercises and other health activities from a physical therapist and begins to practice them on his or her own when awake after surgery. In the first few days after surgery, the patient is still bedridden, but can perform a range of activities in bed. In case of total hip replacement, you can practice knee and ankle activities under the premise of fixing the hip, and you can also do static contraction of abdominal and back muscles. As the postoperative pain disappears, hip extension exercises should be started gradually. At this time, it is important to avoid excessive hip flexion and inversion, which have the risk of dislocating the prosthesis. If the surgery is performed with a cemented filling, the hip can be taken out of bed after 3 to 4 days under the protection of a therapist and gradual walking exercises can be performed in a walking aid. If biomaterial fillings are used, the start of walking is delayed until several weeks later. Later on, careful muscle strength and balance exercises are performed. In the case of total knee replacement, straight leg raising exercises and ankle activities to fix the knee joint can be performed in the early postoperative period. After a few days of pain relief, begin and pay particular attention to knee extension exercises to restore the ability to straighten the knee joint. The time to get out of bed for a total knee replacement is the same as for a total hip replacement. However, in practice, many patients are getting out of bed later than this schedule. Patients should not experience significant pain during the exercises. Some patients who perform painful joint stretches to restore range of motion often not only do not help restore joint mobility, but new injuries and inflammation can occur. The most common complication of total hip replacement is sciatic nerve injury, which is mainly manifested by the inability to dorsiflex the ankle joint. It can be watched out for. General edema after surgery can resolve with activity or elevation of the lower extremity, while significant edema should be suspected and ruled out with deep vein thrombosis. Artificial joints have their own life span. Impulsive sports such as running may shorten its life span. Therefore, swimming is recommended as a fitness routine.