Rehabilitation training after fracture can generally be divided into three phases: 1. Early rehabilitation training: Within 1 to 2 weeks after the injury, the affected limb is swollen and painful at this time. The main purpose of functional exercise in this period is to promote the blood circulation of the affected limb to facilitate the reduction of swelling and stabilization of the fracture. The main form of rehabilitation training is isometric contraction of the muscles of the affected limb. Isometric contraction means that the muscles do rhythmic contraction and relaxation without moving the limb joints. The benefit is to prevent muscle atrophy or adhesions and to restore muscle strength. Shi Guodong, Department of Orthopedics, Shanghai No. 1 Rehabilitation Hospital The principle of rehabilitation training in this period is that all other limbs of the body should undergo functional rehabilitation training except for the upper and lower joints at the fracture site which are not moving. 2.Medium-term rehabilitation training: It refers to the period from 2 weeks after the injury to the clinical healing of the fracture, during which the swelling of the affected limb gradually decreases, the pain decreases, some bones are connected to the fracture end, and a large number of bone scabs are gradually formed, and the fracture becomes more and more stable. During this period, in addition to continuing the muscle contraction training of the affected limb, the upper and lower joints of the fracture end can be restored gradually with the help of the rehabilitation therapist, and appropriate functional training can be carried out. In addition, physical therapy can be used to reduce swelling, remove blood stasis and promote the formation of bone scabs. Five to six weeks after the injury, when the fracture has sufficient bone scab formation, the scope and strength of exercise can be further expanded by gradually increasing active joint flexion and extension activities from one joint to several joints to prevent muscle atrophy and avoid joint stiffness. Fractures involving the articular surface often leave a more obvious joint dysfunction, therefore, it is best to start active muscle movement of the affected limb under fixation in about 2 weeks, and to walk in bed without weight on the affected limb after 4 weeks, and to walk under partial weight after 6-8 weeks, so that the mutual extrusion and friction between the articular cartilage surfaces can promote the repair of articular cartilage and restore the articular surface. At the same time, it can also prevent the formation of intra-articular adhesions. The purpose of rehabilitation during this period is to restore the joint movement of the affected limb, continue to strengthen the muscles, and promote the complete recovery of the affected limb function. The rehabilitation training mainly focuses on active activities and weight-bearing exercises of the joints of the affected limb to restore the normal range of motion of each joint and the normal strength of the limb. During the rehabilitation period, physical therapy and walking training can be carried out.