The bone of the chest is called the sternum, which is located in the middle of the chest wall, anteriorly convex and posteriorly concave, and can be divided into three parts: the sternal stalk, the sternal body and the saber process. The sternal stalk is wide at the top and narrow at the bottom, with a jugular vein incision in the middle of the upper edge and a clavicle incision on both sides, which is connected with the clavicle. The sternal stalk connects to the first rib above the lateral edge and is slightly convex with the sternal body, called the sternal angle, which can be clearly touched on the body surface and is flat against the second rib on both sides and is an important marker for counting ribs. The sternal body is rectangular in shape, and the lateral edge is connected to the 2nd-7th ribs. The sternal process is flat and thin, with a large variation in shape and a free lower end. The sternum has the function of protecting the heart, lungs and other important organs and should be protected from sternal fractures.