Splenius Capitis Muscle

Description

Arising from the inferior half of the ligamentum nuchae and the spinous processes of C7 through T3 to T4, the splenius capitis forms a broad, obliquely oriented sheet on the posterolateral neck. Its fibers course superolaterally to insert on the mastoid process of the temporal bone and the lateral third of the superior nuchal line of the occipital bone, lying deep to trapezius and sternocleidomastoid but superficial to semispinalis capitis and longissimus capitis. Medially it approaches the midline nuchal region, while laterally it contributes to the muscular contour behind the ear and along the upper cervical spine. Insertions at the skull base are clear. Functionally, splenius capitis extends the head and neck bilaterally and rotates and laterally flexes the head ipsilaterally when acting unilaterally, a pattern clinicians look for in cervical movement assessment. This posterior neck strap muscle is a common generator of cervicogenic headache and occipital pain syndromes, and its proximity to the greater occipital nerve and occipital artery makes it relevant when planning targeted injections, dry needling, or surgical exposure in the suboccipital region. Palpation and trigger point referral often localize to the mastoid region and occiput. Educators can place this artwork in head and neck anatomy blocks, kinesiology modules on cervical rotation, or dissection guides that layer trapezius, splenius capitis, and the deeper extensors. It also fits well in clinical content on posterior neck pain, whiplash-associated disorders, and interventional pain references that require accurate insertions at the mastoid and superior nuchal line. Anatomical accuracy verified by SciePro's Medical Advisory Board.