(1) Deformity Displacement of the fractured end may cause changes in the shape of the affected limb, mainly in the form of shortening, angulation, and lengthening. (2) Abnormal activity Abnormal activity may occur after fracture in areas where the limb cannot move under normal circumstances. (3) Bone rubbing sound or bone rubbing sensation Bone rubbing sound or bone rubbing sensation can be produced when the two fracture ends rub against each other after the fracture. Sun Yifeng, Department of Orthopedics, Shandong Qianfo Mountain Hospital The diagnosis can be confirmed by finding one of the above three signs, but those who do not see these three signs cannot exclude the possibility of fracture, such as insertion fracture and fracture by crack. In general, the above signs should not be checked for diagnosis because it will aggravate the injury. For further diagnosis, X-rays and, if necessary, CT examinations are indicated!