Everyday Muscle.

Longissimus Cervicis

Erector spinae muscle that reaches the neck — the cervical extension of the longissimus column, bridging the upper thorax and cervical spine.
Function
Extends and laterally flexes cervical spine
Origin
Transverse processes T1-T5
Insertion
Transverse processes C2-C6
Innervation
Posterior rami of spinal nerves