A slang term for the bone located at the rear of the shoulder, the wing bone is formally called the scapula. It likely gains its nickname from its flat, triangular structure, which resembles that of a wing. Wing bones join the upper portions of the arms to the collar bones, and they aid in upper body movement. These bones are well-protected by muscles and are divided into several different parts.
The wing bone rests at the top back of the rib cage, and each body contains two such bones, or shoulder blades. The humerus is another name for the upper arm bone, and it is connected to the collar bone, or clavicle, by the wing bone. Together, these three structures comprise the shoulder bones. Tough bands of fibers called cartilage rest between the bones, providing cushioning and mobility capabilities.
Shoulder blades must be more durable than other bones because they must answer the upper body's movement, support, and strength needs at once. Muscles in the chest, neck, arms, and back attach to the scapula, allowing the bone to assist in moving these structures. Further, the scapula acts as a guidepost between the arms and the upper body, allowing the structures to work together to perform activities that require strength like pushing or lifting.
A curved surface known as the subscapular fossa constitutes the front of each shoulder blade. Portions of this bone are smooth whereas other portions contain ridges. The ridged areas provide support for tendons, while the smooth surface is covered by protective muscle fibers. In addition, an angular dip occurs on top of the fossa, which gives the overall bone increased strength.
The shoulder spine divides back portions of the wing bone into an upper supraspinous fossa and a lower infraspinous fossa. These structures attach to the movement muscles in the arm, shoulders, and back. Two projections called the acromion process and the coracoid process are also located atop the shoulder bone, and they help anchor the shoulder joints and serve as muscular attatchments. The former structure rests at the top tip of the scapula.
Due to its shape, durability, and surrounding muscular structure, major injuries rarely afflict the wing bone. Hard-hitting injuries such as a car accident or a significant fall can fracture the bone, however. Swelling in the shoulder’s back and intense pain upon arm movement are the primary indicators of a broke shoulder blade. In most cases, immobilization devices placed around the damaged area will facilitate the healing process. If significant damage has occurred to surrounding tissues or to certain parts of the wing bone, surgical intervention may be needed.