Suboccipital Muscles

The suboccipital triangle contains the vertebral artery and the suboccipital nerve. Three of the suboccipital muscles make up the boundaries of the triangle: the rectus capitis posterior major, obliquus capitis superior, and the obliquus capitis inferior.

Rectus Capitis Posterior Major

Origin: Spinous process of axis (C2)
Insertion: Lateral half of the inferior nuchal line of the occipital bone
Action: Extension of the head
Innervation: Posterior Primary Ramus of C1
Blood Supply: Branches from the vertebral artery

Primary Actions of the Rectus Capitis Posterior Major:

1. Extension of the head on the neck when acting bilaterally

  • Agonists: Rectus Capitis Posterior Minor, Obliquus Capitis Superior
  • Antagonists: Rectus Capitis Anterior

2. Ipsilateral rotation of the cervical spine when acting unilaterally

  • Agonists: Obliquus Capitis inferior
  • Antagonists: Obliquus Capitis inferior on the opposite side
Rectus Capitis Posterior Major Muscle

Rectus Capitis Posterior Minor:

Origin: Posterior tubercle of atlas (C1)
Insertion: Lateral half of the inferior nuchal line of the occipital bone.
Action: Extension of  the head
Innervation: Posterior Primary Ramus of C1
Blood Supply: Branches from the vertebral artery

Primary Actions Rectus Capitis Posterior Minor:

1. Extension of the head on the neck when acting bilaterally

  • Agonists: Rectus Capitis Posterior Major, Obliquus Capitis Superior
  • Antagonists: Rectus Capitis Anterior

2. Ipsilateral rotation of the cervical spine when acting unilaterally

  • Agonists: Obliquus Capitis inferior
  • Antagonists: Obliquus Capitis inferior on opposite side
Rectus Capitis Posterior Minor Muscle

Obliquus Capitis Superior

Origin: Superior surface of the transverse process of C1 (atlas)
Insertion: Lateral half of the inferior nuchal line of the occipital bone
Action: Extension of the head, lateral flexion of the head
Innervation: Posterior Primary Ramus of C1
Blood Supply: Branches from the vertebral artery

Primary Actions Obliquus Capitis Superior:

1. Extension of the head on the neck when acting bilaterally

  • Agonists: Rectus Capitis Posterior Major, Rectus Capitis Posterior Minor
  • Antagonists: Rectus Capitis Anterior

2. Lateral flexion of the head on the neck when acting unilaterally

  • Agonists: Rectus Capitis Lateralis
  • Antagonists: Rectus Capitis Lateralis on opposite side
Obliquus Capitis Superior Muscle

Obliquus Capitis Inferior

Origin: Lateral surface of the spinous process and adjacent laminae of C2 (axis)
Insertion: Inferoposterior aspect of the transverse process of C1 (atlas)
Action: Rotates the head to the contracted side
Innervation: Posterior Primary Ramus of C1
Blood Supply: Branches from the vertebral artery

Primary Actions of the Obliquus Capitis Inferior:

1. Ipsilateral rotation of the cervical spine when acting unilaterally

  • Agonists: Rectus Capitis Posterior Major
  • Antagonists: Rectus Capitis Posterior Major on the opposite side
Obliquus Capitis Inferior Muscle

For pain and symptom information see: Suboccipital Muscles Pain and Symptoms

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