The sternocleidomastoid is a prominent muscle on the side of the neck. It originates from the sternum and clavicle and inserts into the mastoid process of the temporal bone. It rotates the head to the opposite side, flexes the neck, and assists in lateral flexion. It is the most visible neck muscle and is often tight in people with poor posture.

Níl aon chleachtadh sa chatalóg dírithe ar an matán seo go fóill.