Obliquus Capitis Inferior: The obliquus capitis inferior is the most inferiorly positioned of the suboccipital muscles. It is situated under the deep cervical vein and comprises the inferior boarder of the suboccipital triangle.Additionally, it is the only capitis muscle that has no attachment to the cranium.
Origin: Base of the spinous process and adjoining lamina of the axis.
Insertion: It inserts into the transverse process of C1.
Function: Extension and rotation of the head.
Nerve Supply: Suboccipital nerve (posterior ramus of C1)
Blood Supply: Obliquus Capitis Inferior receive blood from the Vertebral artery and the deep descending branch of the occipital artery.