The acromion (Greek for “shoulder bone”, syn. acromion, shoulder height) is the lateral end of the scapula (spina scapulae). In humans, the acromion forms the highest point of the shoulder blade. It is a flattened bony process that lies at the lateral end of the shoulder blade.
Function of the acromion
Together with the clavicle, the acromion forms the bony foundation of the shoulder. On the one hand, it serves as the point of origin of muscles, and on the other hand it forms an articulated connection with the adjacent clavicle, allowing the shoulder to be rotated against the clavicle.
The acromion is divided into different areas, with the upper area (Facies superior) being the starting point for different muscles. The following parts of the acromion are roughened and serve as the point of origin for the deltoid muscle: The other two parts of the deltoid muscle find their origin at other parts of the shoulder. Their common point of origin is a roughened surface on the humerus (Tuberositas deltoidea).
The deltoid muscle has various functions: At the lateral edge of the shoulder blade, the bone lies directly under the skin and can be easily palpated here. At the medial edge of the acromion, it forms an articulated connection with the collarbone (clavicle). This joint is called the acromioclavicular joint (Articulatio acromioclavicularis).
In this joint, the shoulder blade (scapula) rotates against the clavicle. The restriction of this movement is mainly caused by the ligament between acromion and clavicle (Ligamentum acromioclaviculare). – upper surface (Facies superior)
- Lateral (lateral) edge of the acromion
- It determines the contour of the shoulder
- It is involved in almost all movements of the shoulder. Its main function, however, is the spreading movement of the arm in the shoulder to the side (abduction).