Sternocleidomastoid Muscle
The sternocleidomastoid muscle, AKA sternomastoid or SCM muscle takes its name from its connection to three bony structures.
- The sternum or breastbone
- The clavicle or collarbone
- Mastoid process of the occipital bone of the skull
Origin: The clavicular division originates at the superior medial third of the clavicle and the sternal division originates at the superior manubrium of the sternum. Insertion: Both divisions of sternocleidomastoid muscle are inserted into the mastoid process of the skull. Action:
- Rotate the head to the opposite side
- Oblique rotation and lifting the head
- Neck Flexion
- Assist scalene in inspiration
- The cervical plexus nerve of the sternocleidomastoid provides proprioception, spacial body orientation in static posture and during movement. [ref]Neck proprioception and spatial orientation in cervical dystonia[/ref]
