neck pain treatment

The sternocleidomastoid muscle is a two-headed neck muscle, which true to its name bears attachments to the manubrium of sternum (sterno-), the clavicle (-cleido-), and the mastoid process of the temporal bone (-mastoid).
It is a long, bilateral muscle of the neck, which functions to flex the nethe sternum (sterno-), the clavicle (-cleido-), and the mastoid process of the temporal bone (-mastoid).
The muscle is closely related to certain neurovascular structures that pass through the neck on their way either to the head or to the periphery of the body.
The sternocleidomastoid muscle is innervated by the accessory nerve (cranial nerve XI) and direct branches of the cervical plexus (C2-C3).
A unilateral contraction of the sternocleidomastoid muscle flexes the cervical vertebral column to the same side (lateral flexion) and rotates the head to the opposite side.
A bilateral contraction elevates the head by dorsally extending the upper cervical joints. At the same time, it flexes the lower cervical column causing an overall bending of the neck towards the chest.
If the head is fixed, it elevates the sternum and clavicle and, thus, expands the thoracic cavity (inspiratory breathing muscle).