Rectus capitis posterior major muscle

The rectus capitis posterior major (or rectus capitis posticus major) is a muscle in the upper back part of the neck. It is one of the suboccipital muscles. Its inferior attachment is at the spinous process of the axis (first cervical vertebra); its superior attachment is onto the outer surface of the occipital bone on and around the side part of the inferior nuchal line. The muscle is innervated by the suboccipital nerve (the posterior ramus of cervical spinal nerve C1). The muscle acts to extend the head and rorate the head to its side.

Anatomy
The rectus capitis posterior major muscle is one of the suboccipital muscles. It forms the superomedial boundary of the suboccipital triangle.

The muscle extends obliquely  superiolaterally from its inferior attachment to its superior attachment.   It becomes broader superiorly.

Attachments
Its inferior attachment is (via a pointed tendon ) at (the external aspect of) the (bifid)  spinous process of the axis (cervical vertebra C2).

Its superior attachment is at (the lateral portion of  ) the inferior nuchal line and the surface of the occipital bone just inferior to this line.  

Innervation
The muscle receives motor innervation from the suboccipital nerve (the posterior ramus of cervical spinal nerve C1). 

Relations
Superiorly, as the two muscles diverge laterally, they create between them a triangular space in which parts of the two recti capitis posteriores minores muscles are exposed.

Actions/movements
The muscle extends the head and (acting together with the obliquus capitis inferior muscle ) ipsilaterally rotates the head. 

Function
Its main actions are to extend and rotate the atlanto-occipital joint.

Research
A soft tissue connection bridging from the rectus capitis posterior major to the cervical dura mater was described in 2011. Various clinical manifestations may be linked to this anatomical relationship. It has also been postulated that this connection serves as a monitor of dural tension along with the rectus capitis posterior minor and the obliquus capitis inferior.