The four main clinical manifestations following a fracture are as follows: first, swelling and pain due to irritation of the fracture end to the surrounding soft tissues and bleeding from the fracture end, which is encapsulated in the soft tissues. Secondly, mobility impairment, due to painful stimulation, muscle tension and loss of bone support, will cause the above changes. Third, a certain sensation of bone rubbing, which can be heard when the fracture ends rub against each other and can be better judged by a stethoscope. Fourth, paradoxical activity, because the supporting force of the fracture disappears after the fracture, when the activity is forced, it will not move at the joint but at the fracture site. Only the third and fourth clinical manifestations are rarely used at present, because the pain will be aggravated when this manifestation is done, and most of them are clearly judged directly under the X-ray examination.