Suboccipital Anatomy

Suboccipital Muscles

Rectus Capitis Posterior MajorMuscle

Rectus Capitis Posterior Major Muscle

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 Muscle

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 Minor Muscle

Rectus Capitis Posterior Minor

Origin: Posterior tubercle of atlas (C1)
Insertion: Medial 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 Minor Muscle

1. Extension of the head on the neck when acting bilaterally
Agonists:
  • Rectus Capitis Posterior Major
  • Obliquus Capitis Superior
Antagonists:
  • Rectus Capitis Anterior
Obliquus Capitis Superior Muscle

Obliquus Capitis Superior Muscle

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 of the Obliquus Capitis Superior Muscle

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 Inferior Muscle

Obliquus Capitis Inferior Muscle

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 Muscle

1. Ipsilateral rotation of the cervical spine when acting unilaterally

Agonists:

  • Rectus Capitis Posterior Major

Antagonists:

  • Rectus Capitis Posterior Major on opposite side

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