Splenius muscle

The splenius muscle is a group of muscles located in the back of the neck and upper thoracic region. It is divided into two distinct muscles: the splenius capitis and the splenius cervicis.

Anatomy

The splenius muscles originate from the nuchal ligament and the spinous processes of the seventh cervical (C7) to the sixth thoracic (T6) vertebrae. The splenius capitis inserts onto the mastoid process of the temporal bone and the occipital bone, while the splenius cervicis inserts onto the transverse processes of the first to third cervical vertebrae (C1-C3).

Innervation

The splenius muscles are innervated by the posterior rami of the spinal nerves.

Function

The primary functions of the splenius muscles are to extend, rotate, and laterally flex the head and neck. When both sides of the muscles act together, they extend the head and neck. When one side acts, it rotates and laterally flexes the head to the same side.

Clinical significance

Tightness or strain in the splenius muscles can lead to neck pain and headaches. These muscles are often involved in conditions such as tension headaches and cervical spondylosis.

See also

• Muscles of the back
• Cervical vertebrae
• Muscle innervation

References

• Gray's Anatomy
• Clinical Anatomy by Regions