Atlanto-occipital joint

The Atlanto-occipital joint (articulation between the atlas and the occipital bone) consists of a pair of condyloid joints. The atlanto-occipital joint is a synovial joint.

Ligaments

The ligaments connecting the bones are:

• Two Articular capsules
• Posterior atlantoöccipital membrane
• Anterior atlantoöccipital membrane

Motions

The movements permitted in this joint are:

• (a) flexion and extension in the frontal axis, which give rise to the ordinary forward and backward nodding of the head.

• (b) slight lateral motion, lateroflexio, to one or other side in the sagital axis.

Flexion is produced mainly by the action of the Longi capitis and Recti capitis anteriores; extension by the Recti capitis posteriores major and minor, the Obliquus superior, the Semispinalis capitis, Splenius capitis, Sternocleidomastoideus, and upper fibers of the Trapezius.

The Recti laterales are concerned in the lateral movement, assisted by the Trapezius, Splenius capitis, Semispinalis capitis, and the Sternocleidomastoideus of the same side, all acting together.

Tension-like Headaches

The Atlanto-occipital joint features predominantly in the symptom of tension-like headaches as a result of prolonged inappropriate posture from poor ergonomic adaptation.

In such cases, patients typically report cracking of the neck, discomfort when sitting, continuous migraine-like headaches, dullness, dizziness, tingling in the fingers, sensitivity to light and a feeling the head is expanding.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.