Sternocleidomastoid - Muscle Physiology & Functional Anatomy


Sternocleidomastoid Muscle




  • Manubrium sterni, medial portion of the clavicle


  • Mastoid process of the (temporal bone) skull, superior nuchal line

Major Arteries:

  • Occipital artery

  • Superior thyroid artery


Neural Innervation:

  • Acessory nerve C1-C5 (motor function)

  • Cervical plexus (sensory function)


Trigger Points:

Trigger Points of the SternocleidomastoidSternocleidomastoid Trigger Points




Concentric Functions:

  • Flexion, rotation, lateral flexion of the (cervical spine) neck

  • Flexion, rotation, lateral flexion & extension of the (atlantooccipital & atlantoaxial) head


Eccentric Functions:

  • Decelerates lateral flexion, rotation & flexion of the cervical spine


Isometric Function:

  • Dynamically stabilizes the cervical spine during functional movements


Related Muscles





More Images of the Sternocleidomastoid Muscle


Sternocleidomastoid and neck


Sternocleidomastoid Muscle

More Information about the Sternocleidomastoid Muscle

The sternocleiodmastoid muscle is commonly abbreviated as SCM.  In addition to its movement functions, this paired muscle aids in inspiration along with the scalene muscles.

The sternocleidomastoid muscle is named so because of its anatomy.  Since it originates at the manubrium of the sternum (sterno) & the clavicle (cleido) and inserts at the mastoid process (mastoid).


Back to Functional Anatomy Chart