Semispinalis Cervicis Detail

musculus semispinalis cervicis detail

Semispinalis cervicis is the largest cervical extensor, spanning from the upper thoracic transverse processes to the mid-cervical spinous processes. It is larger than the semispinalis capitis in the mid-cervical region.

Nerve: Dorsal rami of cervical spinal nerves Blood Supply: Occipital and vertebral artery branches Region: Neck

Anatomical Data

Origin, Insertion & Supply

Origin	Transverse processes of T1-T6
Insertion	Spinous processes of C2-C5 — spanning 5-6 levels
Nerve Supply	Dorsal rami of cervical spinal nerves
Blood Supply	Occipital and vertebral artery branches

Biomechanics

Function & Actions

Actions	Extends the cervical spine — the primary cervical extensor; Contralateral cervical rotation

Clinical Relevance

Clinical Notes

Semispinalis cervicis is the primary target of suboccipital and cervical paraspinal trigger point injections for cervicogenic headache. Its denervation from posterior cervical surgery is a significant contributor to post-laminectomy cervical kyphosis.

Palpation

Palpated as the dominant bilateral cervical extensor mass lateral to the spinous processes.

Pathology

Common Injuries & Conditions

Semispinalis Cervicis Denervation in Cervical Kyphosis

Loss of semispinalis cervicis function after posterior cervical laminectomy contributing to progressive cervical kyphotic deformity (swan neck deformity).