Connection lost. Please refresh the page.
Online
Get help How to study Login Register
Ready to learn?
Pick your favorite study tool

Suboccipital muscles

Origins, insertions, innervation and functions of the suboccipital muscles.

The suboccipital region is a muscle compartment, located inferior to the external occipital protuberance and the inferior nuchal line. These are anatomical landmarks on the occipital bone of the skull. It is of a pyramidal shape and includes the posterior aspects of the atlas and axis (C1 and C2 vertebrae respectively). This region comprises four pairs of small muscles:

These muscles mainly function as postural muscles but can also contribute to movements of the head.

Contents
  1. Suboccipital triangle
  2. Muscles
    1. Rectus capitis posterior major
    2. Rectus capitis posterior minor
    3. Obliquus capitis inferior
    4. Obliquus capitis superior
  3. Blood supply
  4. Innervation
  5. Actions
  6. Clinical notes
    1. Suboccipital syndrome
    2. Tension headaches
  7. Sources
+ Show all

Suboccipital triangle

Three of the four muscles contribute to the formation of the boundaries of the suboccipital triangle: rectus capitis posterior major, obliquus capitis inferior and obliquus capitis superior. This triangle is a region of the posterior neck containing the vertebral artery and the posterior/dorsal ramus of the first cervical nerve (suboccipital nerve).

The superomedial and superolateral boundaries are formed by the rectus capitis posterior major and obliquus capitis superior respectively. The obliquus capitis inferior forms the inferolateral boundary. The roof of the triangle is formed by semispinalis capitis muscle, which is one of the three parts of a deep intrinsic back muscle. The floor consists of the posterior atlanto-occipital membrane and the posterior arch of the atlas. Located deep to the semispinalis capitis is a layer of fibrous adipose tissue.

Muscles

Rectus capitis posterior major

The rectus capitis posterior major originates from the spinous process of the axis by a pointed tendon. It becomes broader as it ascends and it inserts into the occipital bone at the lateral part of the inferior nuchal line. A triangular space is left between the two muscles resulting in visualisation of the recti capitis posterior minor muscles.

Rectus capitis posterior minor

The rectus capitis posterior minor has its origin at the posterior tubercle of the posterior arch of the atlas. Like the rectus capitis posterior major, it is attached to its origin by a narrowed tendon that broadens as it ascends upwards. Insertion of the muscle is also at the inferior nuchal line on the occipital bone but at the lateral part. There may also be a soft tissue attachment to part of the floor of the suboccipital triangle, namely the posterior atlanto-occipital membrane.

Obliquus capitis inferior

The obliquus capitis inferior is the only suboccipital muscle that doesn’t have an attachment to the cranium. It instead inserts into the transverse process of the atlas on the inferoposterior part. Its origin is at the posterior tubercle of the posterior arch of the axis.

Obliquus capitis superior

The obliquus capitis superior is smaller than the obliquus capitis inferior and originates from the transverse process of the atlas. It ascends dorsally, whilst expanding in width, to insert between the superior and inferior nuchal lines, on the occipital bone, laterally to semispinalis capitis.

Blood supply

All of the suboccipital muscles are supplied by the vertebral artery as well as by the deep descending branches of the occipital artery.

Innervation

The four pairs of muscles are all innervated by the posterior ramus of the first cervical nerve/spinal nerve C1, the suboccipital nerve.

Actions

As mentioned above, the main action of the suboccipital muscles is to maintain posture. However, they can also produce movements of the head. These movements include extension, lateral flexion and rotation at the atlanto-axial joints and are summarised below:

  • Rectus capitis posterior major – extension and rotation to the ipsilateral side
  • Rectus capitis posterior minor – extension and rotation to the ipsilateral side
  • Obliquus capitis inferior – rotation to the ipsilateral side
  • Obliquus capitis superior – extension and lateral flexion

Flexion and rotation of the head in the contralateral direction are other movements at the atlanto-occipital joint but are carried out by other muscles in the neck.

Test yourself with this quiz about the main muscles of the head and neck.

Suboccipital muscles: want to learn more about it?

Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster.

What do you prefer to learn with?

“I would honestly say that Kenhub cut my study time in half.” – Read more.

Kim Bengochea Kim Bengochea, Regis University, Denver
© Unless stated otherwise, all content, including illustrations are exclusive property of Kenhub GmbH, and are protected by German and international copyright laws. All rights reserved.

Register now and grab your free ultimate anatomy study guide!