Splenius Capitis Muscle Beneath the Skin, Posterior View

Description

Running obliquely from the midline of the posterior neck toward the lateral skull, the splenius capitis is highlighted beneath the skin, its broad fibers spanning from the nuchal ligament and upper thoracic spinous processes toward the mastoid process and lateral superior nuchal line. Inferior and slightly lateral, splenius cervicis continues the same fiber direction toward the transverse processes of the upper cervical vertebrae, forming a paired sheet deep to the superficial back muscles. Superficial to both splenii, trapezius covers the posterior cervical triangle and upper thorax, while the deltoid caps the lateral shoulder and the rhomboid region sits medial to the scapular spine. Laterally, the splenius capitis borders the posterior edge of the sternocleidomastoid region. Clear separation of layers matters. Clinically, this posterior exposure is the one you want when teaching cervical extension and ipsilateral rotation mechanics, because the splenii sit in the intermediate layer between trapezius and the deeper transversospinalis group (semispinalis capitis and cervicis). Hypertonicity and trigger points in splenius capitis commonly refer pain to the occiput and temporal region and can mimic cervicogenic headache after whiplash, while asymmetric activation contributes to postural torticollis patterns. For posterior cervical approaches and suboccipital injections, the splenius capitis serves as a practical landmark on the way to deeper planes where the greater occipital nerve and occipital artery traverse near the superior nuchal line. Use this illustration in gross anatomy and kinesiology teaching to clarify layer relationships in the posterior neck and upper back, or in rehabilitation materials addressing neck rotation, extension bias, and myofascial pain patterns. It also suits surgical atlases and clinical slide decks that need a clean, posterior, male surface-to-intermediate layer correlation. Anatomical accuracy verified by SciePro's Medical Advisory Board.