Everyday Muscle.

Semispinalis Cervicis

Deep neck extensor/rotator — part of the transversospinalis group, spanning multiple cervical segments for precise neck control.
Function
Extends and contralaterally rotates cervical spine
Origin
Transverse processes T1-T6
Insertion
Spinous processes C2-C5
Innervation
Posterior rami of spinal nerves