Synovial joint between occipital condyle above and facet on superior surface of lateral mass of atlas
Anterior atlanto-occipital membrane: continuation of anterior longitudinal ligament. Connects anterior arch of atlas to anterior margin of foramen magnum
Posterior atlanto-occipital membrane: similar to ligamentum flavum, connects posterior arch of atlas to posterior margin of foramen magnum
Flexion, extension and lateral flexion possible. No rotation
