The rectus capitis posterior minor is the deepest and most medial of the suboccipital muscles, lying medial to the rectus capitis posterior major. Unlike the major, it arises from the atlas rather than the axis, spanning only the atlantooccipital joint and having no rotational function. It is small but has attracted significant research interest due to its direct myodural bridge connection to the posterior atlanto-occipital membrane and the underlying spinal dura.
| Origin | Posterior tubercle of the posterior arch of the atlas (C1) |
|---|---|
| Insertion | Medial part of the inferior nuchal line and the occipital bone between the inferior nuchal line and the foramen magnum |
| Nerve Supply | Suboccipital nerve (posterior ramus of C1) |
| Blood Supply | Vertebral artery; Occipital artery |
| Actions | Extension of the head at the atlantooccipital joint |
|---|
The rectus capitis posterior minor has a proportionally high density of muscle spindles and Golgi tendon organs compared to most muscles, suggesting a proprioceptive role in craniocervical position sense. Research has shown that the myodural bridge from this muscle to the spinal dura is highly consistent, and disruption of this connection through atrophy (as seen in chronic whiplash patients on MRI) correlates with dural adhesion and cervicogenic headache symptoms. This is an active area of manual therapy and pain science research.
Palpated in the deep suboccipital midline, immediately inferior to the external occipital protuberance. Because it is overlaid by semispinalis capitis and rectus capitis posterior major, direct palpation is difficult; sustained digital pressure directed superiorly into the suboccipital space is required.
Hypertonicity and trigger points within the rectus capitis posterior minor, sometimes with atrophy visible on MRI in chronic whiplash patients, contribute to upper cervical stiffness, deep suboccipital aching, and dural-mediated vertex and frontal headache, responsive to suboccipital inhibition and release techniques.
