Semispinalis Capitis
Musculus semispinalis capitis
A large, deep posterior neck extensor lying beneath the splenius that powerfully extends the head and cervical spine and helps hold the head upright. It is a major contributor to posterior neck girth and extension strength developed in neck-extension training, and its overactivity is linked to cervicogenic (tension) headaches via the greater occipital nerve.
- Actions
- Head and cervical extension (bilateral), Contralateral rotation of the head (unilateral), Postural stabilization of the cervical spine
- Origin
- Tips of the transverse processes of T1-T6 and the articular processes of C4-C7.
- Insertion
- Between the superior and inferior nuchal lines of the occipital bone.
- Innervation
- Posterior (dorsal) rami of the cervical spinal nerves (including the greater occipital nerve, C2).
- Blood supply
- Occipital, deep cervical, and vertebral arteries.
Tendons Nuchal Ligament