The obliquus capitis inferior muscle () is a muscle in the upper back of the neck. It is one of the suboccipital muscles. Its inferior attachment is at the spinous process of the axis; its superior attachment is at the transverse process of the atlas. It is innervated by the suboccipital nerve (the posterior ramus of first cervical spinal nerve). The muscle rotates the head to its side.
Despite what its name suggest, it is the only capitis (Latin: "head") muscle that does not actually attach to the skull.
Anatomy
The obliquus capitis inferior is one of the suboccipital muscles (and the only one of these to have no attachment to the skull). It is larger than the obliquus capitis superior muscle. It forms the inferolateral boundary of the suboccipital triangle.
The muscle extends laterally and somewhat superiorly from its inferior attachment to its superior attachment. of the axis (cervical vertebra C2) It is believed that proprioception may be the primary role of the inferior oblique (and indeed the other suboccipital muscles), allowing accurate positioning of the head on the neck.
Additional images
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File:Obliquus capitis inferior muscle animation small.gif|Position of obliquus capitis inferior muscle (shown in red).
File:Obliquus capitis inferior muscle closeup animation small.gif|Close up. Vertebral column, occipital bone and obliquus capitis inferior muscle. The muscle arises from the apex of the spinous process of the axis and insert into the lower and back part of the transverse process of the atlas.
File:Suboccipital triangle dissection.jpg|Obliquus capitis inferior's relationship to other suboccipital muscles.
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See also
Suboccipital muscles