Sternocleidomastoid region

The sternocleidomastoid region refers anatomically to the area of the neck occupied by the sternocleidomastoid (SCM) muscle, which is a prominent, paired muscle running obliquely from the manubrium of the sternum and the medial portion of the clavicle (inferior attachments) to the mastoid process of the temporal bone and the superior nuchal line of the occipital bone (superior attachments).

This region is clinically significant due to its proximity to major neurovascular structures, including the carotid artery, internal and external jugular veins, and several cervical nerves.