Splenius capitis

Origin

The splenius capitis muscle originates from the spinous processes of the seventh cervical (C7) vertebra. It also originates from the upper thoracic vertebraeHeart-shaped body, long downward spinous process, and facets for rib attachment. (T1-T3).

Insertion

This muscle inserts into the mastoid processLarge, rounded bump behind the ear; attachment for neck muscles. of the temporal boneBones on the sides of the skull near the ears; house structures of hearing and balance. and the occipitalPosterior and base of the skull; curves under to form the back of the head. bone.

Actions

Neck Extension

Lateral Flexion of the Neck

Rotation of the Head

The splenius capitis is a “hidden gem” neckNarrow region just below the head; common fracture site. muscle. It doesn’t get the attention of the sternocleidomastoidFlexor / Rotator From sternum and clavicle to skull behind the ear; turns and bends the head. (SCM). However, it’s crucial for headRounded proximal end that fits into the acetabulum of the hip bone. and neck movementA fundamental property of life involving motion of the body or its parts.. Think of it as a strong strap running from the upper spineProminent ridge on the posterior scapula dividing it into supraspinous and infraspinous fossae. to the skull. This strap helps you tilt and turn your head with control.

Location & Attachments:
The splenius capitis originates from the lower half of the nuchal ligament. This is a strong band along the back of the neck. It also originates from the spinous processes of C7–T3 or T4 vertebrae. From there, its fibers run upward and outward like a fan. They insert on the mastoid process of the temporal bone (that bump you can feel just behind your ear). Additionally, they insert on the lateralAway from the midline of the body. part of the superiorAbove or toward the upper part of the body. nuchal line of the occipital bone. That means it ties your upper thoracic and lower cervical spine directly to the back of your head.

Functions:

• Unilateral contraction (one side at a time) makes the head rotate and bend laterally toward that side. Imagine trying to glance over your shoulder—that’s the splenius capitis at work.
• Bilateral contraction (both sides together) extends the head and neck, like when you look upward toward the ceiling.
  In short: it’s part of your “look up, look around” toolkit.

Clinical Note:
Tightness in the splenius capitis often contributes to tension headaches. It can also lead to neck stiffness. This is because it atta