The coracoid bone (lat. os coracoidea; synonym: os deltoideum, ostium externum) is the only sesamoid bone of the forearm and connects the scapula with the deltoid muscle. All the muscles of the shoulder girdle are attached to it, with the exception of the subscapularis muscle, which is attached to the back surface of the scapula. It is sometimes believed that it is named for the beak-like shape in which it protrudes on the shoulder blade. However, upon closer examination, it is easy to see that this shape is given to it by the depression of the scapula and the angle of the spinal joint that drains the position of the limb.
On the outside, the bone is covered by the deltoid, latissimus dorsi and pectoralis major muscles (m. pectoralis major), they form the notch of the sternum, bounded by the coracoid bone on one side and the subclavian bone on the other.
The bone enters the body of the scapula first