Signs specific to fracture include the following: 1. deformity: divided into shortening deformity and angular deformity, such as bilateral asymmetry of the limb, abnormal angularity and other symptoms; 2. abnormal activity: parts of the limb that cannot move under normal circumstances appear abnormal activity after fracture, such as abnormal activity of the wrist joint and the middle joint of the elbow joint after fracture; 3. bone rubbing sensation: the two fracture ends rub against each other after fracture, and the patient can feel abnormal friction between bone and bone. If the above three conditions occur, the patient can be judged to have a fracture phenomenon.