Semispinalis Capitis
Back
A major deep neck extensor — one of the thickest muscles at the back of the neck. Often palpable as the thick bilateral ridges running from the upper back to the skull.
Function
Extends head; contralaterally rotates head
Origin
Transverse/articular processes C4-T6
Insertion
Occipital bone between superior and inferior nuchal lines
Innervation
Posterior rami of spinal nerves