The Functional anatomy of semispinalis capitis is significant when it comes to upper cervical pain. It attaches to the occiput and then usually skips the first three cervical vertebrae. After that, it has variable attachments to the vertebrae from C4 through T7.
Greater Occipital Nerve Involvement
The greater occipital nerve is structurally vulnerable to the tension in semispinalis capitis. This nerve branches off of the C3 dorsal ramus below the posterior arch of the atlas. The palpable tension of this nerve at its emergence is a reliable indicator of atlas displacement. It winds around the lower border of obliquus capitis inferior. Then, it passes superficial to the suboccipital muscles. The nerve extends superiorly until it pierces semispinalis capitis and emerges deep to the trapezius. It passes through the attachment tendon on the superior nuchal line near the external occipital protuberance. It then passes under the galea aponeurosis.
Tension in semispinalis capitis entraps the greater occipital nerve, creating posterior head pain and paraesthesia.
Variations in Attachments
Dissection studies vary in their report of attachments on the thoracic vertebrae. They show that they not only differ in which vertebrae are attached but also that some slips attach to the transverse or spinous processes.
Summary of Attachments
Origin – transverse processes of C7-T6 or T7 and the articular processes of C4-C6
Insertion – Between the superior and inferior nucal ridges of the occipital ridge
Function – Extension and some rotation of the head
Semispianlis Capitis is part of the semispinalis muscle group. The other two muscles are the interspinous muscles; semispinalis cervicis and semispinalis thoracis. These muscles are deep to the extrinsic back muscles and superficial interspinous muscles. They provide another layer of paraspinal erectors to support the cervical muscles on the thoracic column.
All of these muscles all have statistically significant variations in their structure.
Note how the atlas is skipped so that these muscles easily render it in an anterior displacement.
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Tony Preston has a practice in Atlanta, Georgia where he sees clients. He has written and taught about anatomy, trigger points, and cranial therapies since the mid-90s.
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to include more patterns with better self-care. In the meanwhile, there will be inconsistency in formatting, content, and readability until we get the old posts updated. Please excuse our mess.