The obliquus capitis superior is one of the four suboccipital muscles, forming the superolateral boundary of the suboccipital triangle. It runs superiorly and medially from the transverse process of the atlas to the occipital bone between the nuchal lines. Together with the obliquus capitis inferior and rectus capitis posterior major it forms the suboccipital triangle, the floor of which contains the vertebral artery, suboccipital nerve, and suboccipital venous plexus.
| Origin | Transverse process of the atlas (C1) |
|---|---|
| Insertion | Occipital bone between the superior and inferior nuchal lines, lateral to the semispinalis capitis insertion |
| Nerve Supply | Suboccipital nerve (posterior ramus of C1) |
| Blood Supply | Vertebral artery; Occipital artery |
| Actions | Extension of the head; Ipsilateral lateral flexion of the head |
|---|
The obliquus capitis superior is an important landmark during posterior craniocervical surgery, where its transverse process attachment defines the lateral boundary of the suboccipital exposure. The vertebral artery, passing through the suboccipital triangle, is the critical structure protected during suboccipital decompression and C1-C2 fusion. Suboccipital trigger points involving the obliquus capitis superior refer pain superiorly into the parietal region and posteriorly into the occiput.
Palpated in the lateral suboccipital region, from the posterior aspect of the C1 transverse process (palpable approximately 1.5 cm inferior to the mastoid tip) toward the occipital bone. The patient should be prone with the head in neutral to minimise overlying muscle tension.
Active trigger points within the obliquus capitis superior produce a characteristic referral pattern to the ipsilateral parietal and temporal region, contributing to suboccipital and cervicogenic headache managed with manual therapy, dry needling, or suboccipital nerve block.