After a humerus fracture, whether the patient has undergone surgical internal fixation or external fixation in a cast or splint, it is necessary to start rehabilitation exercises immediately after fixation, to the extent that they are not strenuous. To train the functional exercises of the fingers, palm and wrist, do fist clenching exercises, five-finger extension exercises, wrist dropping or wrist lifting exercises every day, and exercise the muscles of the forearm to keep the finger joints, metacarpal joints and wrist joints in a normal state of motion, which can indirectly promote blood circulation in the arm and promote peripheral blood flow back to achieve the purpose of swelling and pain relief. Immediately after the fracture is fixed, shrugging exercises should be performed to allow the shoulder joint and the muscles and ligaments around the joint to move to promote circulation and prevent atrophy. After a month or so of fixation, you should start functional exercises for the elbow joint, as much as you can within your ability every day, so that the elbow joint can reach its normal range of motion as soon as possible. After the fracture heals, gradually increase the range of motion of the arm to promote the return of the muscles of each joint to their normal state.