Splenius Capitis

Description

Obliquely oriented splenius capitis fibers are seen on the posterolateral neck, spanning from the midline nuchal ligament and spinous processes of the upper thoracic vertebrae (classically T3 to T4) toward the lateral skull. Superiorly, the muscle inserts 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 posterior to the sternocleidomastoid that dominates the anterolateral cervical contour. The mandible, cranial base, and cervical vertebrae provide firm bony landmarks, while the clavicle, scapula, and proximal humerus frame the lower field and help orient neck to shoulder relationships. Clinically, splenius capitis is a common generator of cervicogenic headache and myofascial trigger points that refer pain toward the occiput and behind the ear, a pattern often confused with migraine or occipital neuralgia. Its line of pull explains ipsilateral rotation and lateral flexion of the head, and the lateral skull attachment makes it a practical landmark when teaching posterior cervical layers during a posterolateral neck dissection. Palpation and injection strategies also depend on recognizing its depth relative to trapezius and its position posterior to the sternocleidomastoid. Suitable for gross anatomy teaching of the head and neck, rehabilitation and sports medicine texts on cervical muscle function, and clinical education materials on neck pain referral patterns and manual therapy landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.