Acromion

The acromion is the highest point of the shoulder and is a flat, triangular (or oblong) bony process located on the scapula. It projects laterally from the spine of the scapula and then curves forward and upward, forming a protective overhang above the glenoid cavity.

• Superior surface: Convex and rough, it is subcutaneous and can be palpated. It provides attachment for the deltoid muscle.

• Inferior surface: Smooth and concave, and faces the shoulder joint.

• Lateral border: Thick and irregular, with three or four small tubercles where the deltoid muscle's tendons attach.

• Medial border: Shorter and concave, it attaches to the trapezius muscle and features a small oval facet for articulation with the clavicle.

• Apex: Located at the meeting point of the medial and lateral borders, it is thin and serves as the attachment site for the coracoacromial ligament.