The suboccipital muscles are comprised of eight muscles total (one set of four on either side). The suboccipital muscles are not very well known to people, but after today’s post, you should get a better idea of their significance.
The rectus capitus posterior major originates from the axis (C2) spinous process, and then inserts into the lateral part of the inferior nuchal line of the occiput. This muscle’s primary action is to extend the head and rotate it to the same side. It is innervated by the suboccipital (C1) nerve.
The rectus capitus posterior minor begins at the tubercle of the atlas (C1) posterior arch and inserts into the medial aspect of the nuchal line on the occiput, near where the rectus capitus posterior major inserts. This muscle extends the head only, and is innervated by suboccipital nerve as well.
The obliquus capitus superior originates at the atlas transverse process and inserts into the occiput somewhere between the superior and inferior nuchal lines. This muscle extends the head as well, but also bends the head to the side. Once again, this muscle is innervated by the suboccipital nerve.
The obliquus capitus inferior begins at the apex of the axis spinous process and attaches to the atlas transverse process. This muscle rotates the atlas, as well as turns the head to the same side. It, too, is innervated by the suboccipital nerve.
You can see by looking at the picture that these muscles form a triangle over the upper cervical spine.
The upper cervical spine has been shown to be the most concentrated area of mechano- receptors (joint position receptors) in the body. The suboccipital muscles have been also been shown to have a very dense number of muscle spindle cells and GTOs (Golgi tendon organs). Muscle spindles measure the rate of change in muscle length, monitoring joint position as it relates to the muscle. GTOs measure muscle tension.
When someone develops an upper cervical subluxation, a misalignment of atlas or axis can cause a very substantial alteration in the tone of these suboccipital muscles. It can lead to a tightening on one side or both, which often times can be the cause of tension headaches or cervicogenic headaches.
If you are reading this for the first time and haven’t made an appointment with an Upper Cervical Chiropractor, find one near you and make an appointment immediately. The last thing you want is an upper cervical subluxation interfering with the nerve signals sent to these muscles.
With the highest concentration of receptors in the body found in the upper cervical spine and surrounding muscles, you can’t afford to to be subluxated there.
REFERENCE
1. Erikson, K. Upper Cervical Subluxation Complex. Lippincott Williams & Wilkins, 2003.
Recommended Reading
* Subscribe to The Atlas of Life FREE Monthly Email Newsletter by clicking here!* Become a part of The Atlas of Life Chiropractic Directory today by clicking here!
