The rectus capitis lateralis is a short prevertebral muscle bridging the lateral mass of the atlas to the jugular process of the occipital bone. It is the most lateral of the rectus capitis muscles and lies lateral to the rectus capitis anterior. It is thought to represent the homologue of the posterior intertransversarii in the suboccipital region and is one of the smallest named muscles in the body.
| Origin | Upper surface of the transverse process of the atlas (C1) |
|---|---|
| Insertion | Inferior surface of the jugular process of the occipital bone |
| Nerve Supply | Anterior ramus of C1 (suboccipital nerve) |
| Blood Supply | Vertebral artery; Occipital artery |
| Actions | Lateral flexion of the head to the same side at the atlantooccipital joint |
|---|
Rectus capitis lateralis is rarely mentioned in clinical contexts but is part of the deep prevertebral muscle group that creates fine positional adjustments at the atlantooccipital joint. The vertebral artery runs immediately posterior to this muscle as it exits the transverse foramen of C1, making precise surgical anatomy of this region critical during C1-C2 stabilisation procedures. Needle electromyography of the prevertebral muscles at C1-C2 is rarely performed but theoretically samples this muscle to assess upper cervical root function.
Not directly palpable due to its deep prevertebral location beneath the internal jugular vein, carotid sheath, and upper cervical prevertebral fascia.
Disruption of the fine proprioceptive control provided by rectus capitis lateralis and its neighbours following whiplash or atlantooccipital trauma contributes to upper cervical instability patterns with poor head-on-neck positional control and cervicogenic dizziness.
