The occipitoatlantal (OA) joint is an important component among the complicated anatomy of the suboccipital region. A combination of dysfunction in the motion and positioning of the joint, abnormal tension of nearby musculature and ligamentous structures, and compression of significant cranial and spinal nerves is thought to contribute to pain in certain types of headaches.
1 Osteopathic manipulative treatment applied to this region may improve joint biomechanics, autonomic tone, and circulation of the region.
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The OA joint is composed of the 2 condyles of the occipital bone and the superior articular facets of the atlas, forming a pair of synovial joints.
2(pp736-737) Notable connective tissue structures that connect the 2 bones are the anterior and posterior occipitoatlantal membranes. These 2 membranes fuse with the joint capsules, and the posterior membrane also fuses with the spinal dura. Three of 4 suboccipital muscles—the rectus capitis posterior major and minor and the obliquus capitis superior—cross the OA joint.
2(pp744-745) Together, these muscles serve in a patient's proprioception and postural function, and they may also aid in stabilization.
3 Furthermore, the rectus capitis posterior minor muscle, which originates from the posterior arch of the atlas and inserts onto the inferior nuchal line of the occipital bone, has been shown in some individuals to contain additional connective tissue attaching to the posterior occipitoatlantal membrane, forming what is known as the myodural bridge.
2(pp744-745) Innervation to the OA joint is supplied by the ventral ramus of the C1 cervical nerve.
2(pp744-745)
Approximately 50% of cervical flexion and extension results from the OA joint.
1 Flexion motion at the OA joint occurs with posterior glide of the occiput, while extension motion occurs with anterior glide.
1 Other minor but clinically significant motions of the OA joint include coupled sidebending and rotation in opposite directions.
4 These motions result from the occipital condyles’ convex arrangement on the atlas's concave articular surface, as well as the anterior convergence of the occipital condyles.
1,4,5 Coupled motion of sidebending and rotation involves one occipital condyle gliding anteriorly while another glides posteriorly.
1 Somatic dysfunction of the OA joint may occur because of restriction in the anterior or posterior glide of the occiput or the coupled sidebending and rotation motions resulting from ligamentous or muscular attachments and joint orientation.
1,5 The upper cervical spine region is intimately connected via muscular attachments and ligaments. Somatic dysfunction may stimulate mechanoreceptors and nociceptors in the area, contributing to local and regional symptoms.
3
Muscle energy, which is demonstrated in the
video, is a safe and effective treatment for the OA joint. However, absolute contraindications to performing this technique may include fracture, dislocation, joint instability, neurologic symptoms with rotation of the neck, or patients who are unable or unwilling to follow a physician's verbal instructions, whereas relative contraindications may include severe muscle strains, osteoporosis, spondyloarthropathy, tumors, or severe illness.
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