Splenius capitis

The splenius capitis is a strap-like muscles that, along with the splenius cervicis, comprise the superficial layer of intrinsic back muscles.

Gross anatomy

Attachments
  • origin: ligamentum nuchae, and the tips of the spinous processes and associated supraspinous ligaments of C7 and the upper three to four thoracic vertebrae
  • insertion:  mastoid process and rough surface of the occipital bone below the lateral third of the superior nuchal line
Relations

Blood supply

Innervation

  • lateral branches of the 2 and 3 cervical dorsal rami from the cervical plexus

Action

  • rotates the head to the same side: when acting unilaterally and synergistically with the sternocleidomastoid
  • extends the head: when acting bilaterally