DEFINITION – What does Sternocleidomastoid mean?

One of the biggest superficial muscles in your neck, the sternocleidomastoid, (sternomastoid for short), or better, SCM, is a paired muscle located within the superficial layers of your neck. Thick and rounded in the centre, and wider but thinner at each end, this muscle travels vertically from the manubrium sections of the sternum and clavicle up into the mastoid of the skull’s temporal bone.

FUNCTION – Sternocleidomastoid Muscle

Controlled by the accessory nerve, each of the sternomastoids permit the head to turn left and right respectively, and together, they allow flexion.