The Suboccipital Muscles

Introduction

The suboccipital muscles are a set of four paired muscles in the back of the neck.

The suboccipital muscles attach to the atlas (C1), axis (C2) and occipital bone, connecting the atlas to the axis and the two vertebrae to the base of the skull. They are deep to the trapezius, splenius and semispinalis muscles and superficial to the atlanto-occipital and atlanto-axial joints.

These small muscles contribute to the movements of the head. When the suboccipital muscles contract, they extend the head at the atlanto-occipital joint and rotate the head at the atlanto-axial joints.

Rectus capitis posterior major

Origin

Spinous process of the axis

Insertion

Lateral aspect of the occipital bone, below the inferior nuchal line

Function

Extends the head and rotates the head to the ipsilateral side of the muscle

Innervation

Suboccipital nerve (posterior ramus of C1)

Blood supply

Vertebral artery and deep descending branches of the occipital artery

Rectus capitis posterior minor

Origin

Posterior tubercle of the atlas

Insertion

Medial aspect of the occipital bone, below the inferior nuchal line

Function

Extends the head

Innervation

Suboccipital nerve (posterior ramus of C1)

Blood supply

Vertebral artery and deep descending branches of the occipital artery

Obliquus capitis superior 

Origin

Transverse process of the atlas

Insertion

Between the superior and inferior nuchal lines of the occipital bones

Function

Extends the head and bends it to the ipsilateral side (laterally)

Innervation

Suboccipital nerve (posterior ramus of C1)

Blood supply

Vertebral artery and deep descending branches of the occipital artery

Obliquus capitis inferior  

Origin

Spinous process of the axis

Insertion

Transverse process of the atlas

Function

Rotates the head to the ipsilateral side

Innervation

Suboccipital nerve (posterior ramus of C1)

Blood supply

Vertebral artery and deep descending branches of the occipital artery

The suboccipital triangle

Three of the suboccipital muscles form the boundaries of the suboccipital triangle:

• The medial border of the triangle is formed by the rectus capitis posterior major muscle.
• The lateral border of the triangle is formed by the obliquus capitis superior muscle.
• The inferior border of the triangle is formed by the obliquus capitis inferior muscle.
• The roof of the triangle includes dense connective tissue.
• The floor of the triangle includes the posterior atlanto-occipital membrane and the posterior arch of the atlas.

The contents of the triangle include important structures such as:

• The vertebral artery
• The vertebral vein and suboccipital plexus
• The greater occipital nerve
• The suboccipital nerve

Key points

• The suboccipital muscles are a group of four paired deep muscles located at the base of the occipital bone.
• Their main actions are to extend and rotate the head.
• They consist of the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior and obliquus capitis inferior.
• They are innervated by the suboccipital nerve and their arterial supply comes from the vertebral artery and deep descending branches of the occipital artery.

Editor

Dr Chris Jefferies

References

• Richard L. Drake, A. Wayne Vogyl, Adam W. M. Mitchell. Gray’s Anatomy for Students. 4^th Elsevier. Published in 2019.
• John T. Hansen. Netter’s Clinical Anatomy. 4^th Elsevier. Published in 2018.
• Susan Standring. Gray’s Anatomy. 42^nd Elsevier. Published in 2020.
• Donald A. Neumann. Kinesiology of the Musculoskeletal System. 3^rd Elsevier. Published in 2016.
• Neil S. Norton. Netter’s Head and Neck Anatomy for Dentistry. 3^rd Elsevier. Published in 2016.

Image references

1. Anatomography. The suboccipital muscles. License: [CC BY-SA]
2. Häggström, Mikael (2014). “Medical gallery of Mikael Häggström 2014”. WikiJournal of Medicine 1 (2). License: [Public domain]