As long as the standardized rehabilitation training after the recovery of humerus fracture, the arm will not be unable to straighten forever. After humerus fracture, if the fracture occurs in the middle part of the humerus, the fracture is not displaced, conservative treatment, plaster fixation for 6 weeks, and then rehabilitation exercise, joint flexion and extension exercise, through the exercise generally can move freely. If the fracture has obvious displacement or occurs in the joint fracture, need to take incision and internal fixation, this part of the joint is easy to cause joint stiffness, surgical plate screw internal fixation, 1 month after surgery, passive and active activity exercise. If the exercise is good, it can be straightened, if the exercise is not good, it may affect the straightening. Therefore, the arm will not be unable to straighten forever after recovering from humerus fracture, and most of it can be recovered through rehabilitation exercises.