Suboccipital Triangle : Overview,Boundries & Contents

Suboccipital Triangle :suboccipital triangle contentsThe suboccipital triangle is placed at the back of the junction between head and neck, bounded by the three muscles of the suboccipital muscles:

Obliquus capitis superior – above and laterally
Rectus capitis posterior major – above and medially
Obliquus capitis inferior – below and laterally

Content of Suboccipital Triangle

  • Vertebral artery, which is placed on the posterior arch of atlas
  •  Posterior ramus of first cervical nerve (suboccipital nerve)
  • Suboccipital plexus of veins

Floor & Roof of the Suboccipital Triangle

  • Roof: Semispinalis capitus
  • Floor: Posterior atlanto-occiptal membrane and posterior arch of the C1 vertebrae (atlas)

Cutaneous innervation over the triangle

  • Greater Occipital Nerve- C2 dorsal ramus, upper back of the skull.
  • Lesser Occipital Nerve- Cervical plexus, Lateral part of the back of the skull.
  • Least occipital Nerve- C3 dorsal ramus, inferior medial part of the back of the skull.

Muscles superficial to the suboccipital triangle

  • Muscles of the Suboccipital Triangle(Deep-Superficial)
  • Semispinalis Capitis
  • Splenius Capitis
  • Trapezius

Bones of the suboccipital triangle

  • Occipital Bone, at inferior nuchal line
  • Transverse process of C1
  • Spinous process of C1
  • Spinous process of C2

Nerves innervate or originate within the triangle

  • The suboccipital nerve from dorsal ramus of C1 is the motor innervation of the suboccipital triangle. It passes through the triangle.
  • The greater occipital nerve of dorsal ramus of C2 comes from under the obliquus capitis under and goes superiorly.

Function of the Suboccipital Muscles

Small movements of the head and moreover probably for small movements, stabilization, and proprioception.

Clinical Conditions Commonly Affect the Suboccipital Triangle

  • Cervicogenic Headaches- Begins with hypertonicity in the muscles of the neck and scalp- it compresses the greater occipital nerve causing occipital neuralgia. The treatment is to relax the nerve from the C2 root.
  • Vertebral artery dissection- Once the vertebral artery exits the transverse foramen of C1, it is exposed and can be damaged by various means. This can commence to pooling of blood in the base of the skull and death.