Atlanto-occipital Joint (Neck)

Bones: The occipital bone at the base of the skull and the atlas which is the top of the cervical vertebrae.

Cartilage: There is an articular capsule that cushions the connection between the atlas and the occipital condyles. There are also the vertebral discs between cervical vertebrae.

Muscles: Sternocleidomastoid pulls the head down towards the chest. A complex set of muscles is used to pull and rotate the head, many of them having angular attachments so that they can move the head in multiple directions with each contraction.

Ligaments: There are a multitude of ligaments that run down the back and front of the vertebrae.

Joint type: Pivoting joint.

Mechanics: The complex arrangement of attachments allows for minuted contractions to achieve a large range of motion. The power of the neck moderate, anyone who has had a sore neck knows pain of all the contracting muscles. Seeing as how there is one main muscle for the the downward motion of the head, this can be of great use, pushing the chin into the muscles of an attacker causing a muscle spasm.

Range of motion: About 85 degrees flexing the head forward. About 70 degrees extending the head backwards. About 90 degrees rotation to both the left and the right. About 40 degrees of lateral flexion (tilting the head) to the left and the right.

Injury: Again anyone who has had a sore neck knows pain of the minute contractions of the muscles in the neck. Therefore something such as a chop the to side of the neck would hinder a lot of movement, made worse if ripping occurred at the ligaments between the bones. Also a blow to the back of the head at the base of the skull could do an extreme amount of damage ripping ligaments, and fracturing bones that could induce nerve damage.

Manipulation: Our inner ear is what gives us a sense of balance an acceleration therefore a quick push to the head throws people off a lot. Pushing on the throat to move the person from the neck off balances them as well and puts pressure on the throat. There are also throws that can be done from pushing the chin back until the spine acts like a tether pulling the center of gravity off of the feet. There are a few Dumog throws that use a similar concept pushing on the side of the neck. If the opponent is thrown to the ground on their chest, pressure can be applied to the base of the skull pinning them down as most people need their inner ear to start moving (ie. the lead their body with the head).

For information on additional joints please refer back to the Joints page.