The location of the sacral vertebrae is generally projected on the body surface by the pelvis, that is, the bones on both sides can be felt as the boundary, draw a horizontal line to the middle, which generally corresponds to the 4th lumbar vertebrae, and then count down about 3 horizontal fingers as the boundary is a large piece of bone, which is the sacral vertebrae. The sacral vertebra is a very large bone in the human body, which is connected to the pelvis and the whole trunk. Fractures rarely occur in the sacral vertebra in the human body, unless they are caused by a great fall from height or a great violent injury. The sacral vertebrae are relatively hard in the human body, but what is really prone to fracture is the position between the sacral vertebrae and the pelvis, that is, the sacroiliac joint, which is prone to fracture and dislocation, as well as the position of the ligament complex.