Splenius capitis

The splenius capitis (Latin: musculus splenius capitis) is a broad straplike muscle located in the back of the neck that belongs to the deep or intrinsic muscles of the back. The upper part of the muscle lies deep below the sternocleidomastoid, while its lower part - underneath the trapezius.

Origin

The splenius capitis originates from the lower half of the nuchal ligament and the spinous processes of the seventh cervical to third thoracic vertebrae (C7 - T3).

Insertion

The fibers of the splenius capitis insert into the mastoid process of the temporal bone and the adjacent occipital bone - into its rough surface just below the superior nuchal line.

Action

The main actions provided by the splenius capitis are extension of the head, as well as rotation and lateral flexion of the cervical spine. It is involved in movements such as shaking the head.

Innervation

The splenius capitis is innervated by the posterior branches (dorsal rami) of the third to sixth cervical nerves (C3 - C6).