Atlanto-occipital joint

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Atlanto-occipital joint
Anterior atlantoöccipital membrane and atlantoaxial ligament.
Posterior atlantoöccipital membrane and atlantoaxial ligament.
Latin	articulatio atlantooccipitalis
Gray's	subject #74 295
MeSH	Atlanto-Occipital+Joint
Dorlands/Elsevier	a_64/12160970

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

[edit] Ligaments

The ligaments connecting the bones are:

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

[edit] Motions

The movements permitted in this joint are:

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

• (b) slight lateral motion to one or other side.

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.

[edit] Tension-like Headaches

The Atlanto-occipital joint features predominantly in the symptoms 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.

v • d • e Joints and ligaments of head and neck Craniocervical Atlanto-axial (lat + med) capsule - atlantoaxial ligaments (anterior, posterior) - cruciform ligament of atlas (transverse ligament of the atlas) Atlanto-occipital capsule - membranes (anterior atlantoöccipital membrane - posterior atlantoöccipital membrane - tectorial membrane) alar ligament - ligament of apex dentis Temporomandibular capsule - articular disk lateral (temporomandibular ligament) - medial (sphenomandibular ligament, stylomandibular ligament) Other Cricothyroid articulation - Cricoarytenoid articulation

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.