large flat triangular bone that overlies the posterior thoracic wall

The sternoclavicular joint is indirectly supported by the costoclavicular ligament (costo- = “rib”), which spans the sternal end of the clavicle and the underlying first rib. This joint allows considerable mobility, enabling the clavicle and scapula to move in upward/downward and anterior/posterior directions during shoulder movements. This forms the sternoclavicular joint, which is the only bony articulation between the pectoral girdle of the upper limb and the axial skeleton. The medial end, known as the sternal end of the clavicle, has a triangular shape and articulates with the manubrium portion of the sternum. The clavicle has three regions: the medial end, the lateral end, and the shaft. Finally, it serves to protect the underlying nerves and blood vessels as they pass between the trunk of the body and the upper limb. The clavicle also transmits forces acting on the upper limb to the sternum and axial skeleton. This in turn holds the shoulder joint superiorly and laterally from the body trunk, allowing for maximal freedom of motion for the upper limb. First, anchored by muscles from above, it serves as a strut that extends laterally to support the scapula. The clavicle has several important functions. The clavicle is the only long bone that lies in a horizontal position in the body (see ).

This allows for the extensive mobility of the entire pectoral girdle, which in turn enhances movements of the shoulder and upper limb. In addition, the clavicle of each pectoral girdle is anchored to the axial skeleton by a single, highly mobile joint. The right and left pectoral girdles are not joined to each other, allowing each to operate independently. Both of these bones serve as important attachment sites for muscles that aid with movements of the shoulder and arm. Move your shoulder around and feel how the clavicle and scapula move together as a unit. By following along the clavicle, you can palpate out to the bony tip of the shoulder, and from there, you can move back across your posterior shoulder to follow the ridge of the scapula. This ridge extends out laterally, where it forms the bony tip of the shoulder and joins with the lateral end of the clavicle.

The scapula is a flat, triangular-shaped bone with a prominent ridge running across its posterior surface. It is supported by the clavicle, which also articulates with the humerus (arm bone) to form the shoulder joint. The scapula (shoulder blade) lies on the posterior aspect of the shoulder. The pectoral girdle consists of the clavicle and the scapula, which serve to attach the upper limb to the sternum of the axial skeleton.

Large flat triangular bone that overlies the posterior thoracic wall