Obliquus capitis inferior muscle
Encyclopedia
The obliquus capitis inferior muscle is the larger of the two oblique muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

s of the neck. It arises from the apex of the spinous process
Spinous process
The spinous process of a vertebra is directed backward and downward from the junction of the laminae , and serves for the attachment of muscles and ligaments. In animals without an erect stance, the process points upward and may slant forward or backward...

 of the axis
Axis (anatomy)
In anatomy, the second cervical vertebra of the spine is named the axis or epistropheus.It forms the pivot upon which the first cervical vertebra , which carries the head, rotates....

 and passes laterally and slightly upward, to be inserted into the lower and back part of the transverse process of the atlas
Atlas (anatomy)
In anatomy, the atlas is the most superior cervical vertebra of the spine.It is named for the Atlas of Greek mythology, because it supports the globe of the head....

.

It lies deep to the semispinalis capitis
Semispinalis capitis
The Semispinalis capitis is situated at the upper and back part of the neck, deep to the Splenius, and medial to the Longissimus cervicis and capitis....

 and trapezius muscles.

The muscle is responsible for rotation of the head and first cervical vertebra (atlanto-axial joint
Atlanto-axial joint
The Atlanto-axial joint is of a complicated nature. It consists of no fewer than four distinct joints....

).

It forms the lower boundary of the suboccipital triangle
Suboccipital triangle
The suboccipital triangle is a region of the neck bounded by the following three muscles of the suboccipital group of muscles:* Rectus capitis posterior major - above and medially* Obliquus capitis superior - above and laterally...

 of the neck.

The naming of this muscle may be confusing, as it is the only capitis (L. "head") muscle that does NOT attach to the cranium.

Proprioception

The obliquus capitis inferior muscle, like the other suboccipital muscles, has an important role in proprioception
Proprioception
Proprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...

. This muscle has a very high density of Golgi organs and muscle spindles which accounts for this. 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.
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