Splenius cervicis is one of the superficial muscles of the intrinsic layer within the back. It originates from the:
- spinous processes of vertebrae T3 or T4 to T6
- intervening supraspinous ligaments
Broad and thin, bilaterally it passes superolaterally to insert into the posterior tubercles on the transverse processes of cervical vertebrae C1 to C3 or C4.
Splenius cervicis is innervated by the posterior primary rami of the inferior cervical spinal nerves.
Its actions are:
- acting independently, to assist in ipsilateral rotation and lateral bending of the neck
- acting bilaterally, to extend the cervical spine and pull the head posteriorly
- to 'compress down' deeper layers of cervical spinal muscles