Splenius Cervicis Muscle Beneath the Skin, Lateral View

Description

Lateral soft tissue has been rendered semi-translucent to expose the splenius cervicis along the posterolateral neck, running obliquely from the upper thoracic spinous processes toward the transverse processes of the mid to upper cervical vertebrae. Superiorly it sits deep to the splenius capitis and posterior to the sternocleidomastoid, while its inferior fibers disappear beneath the trapezius and adjacent shoulder fascia. Posterior to the muscle belly, the cervical spinous processes and the column of the cervical vertebrae provide bony orientation; a segment of the carotid sheath region is suggested anterolaterally by a prominent blue vessel consistent with the internal jugular vein. Temporal and masticatory landmarks (temporalis and masseter) anchor the craniofacial profile. Splenius cervicis is a frequent generator of posterolateral neck pain and referred discomfort toward the occiput and upper shoulder, often after whiplash injury or sustained rotation and extension postures, and this lateral relationship to sternocleidomastoid helps explain why patients describe pain that feels both anterior and posterior. Palpation and dry needling or trigger point injection planning depends on knowing what lies superficial (trapezius, splenius capitis) and what lies deep (semispinalis and the cervical laminae) to avoid drifting medially toward the dorsal rami. The included spinalis cervicis reference supports teaching of the erector spinae column and how these deeper extensors sit closer to the spinous processes than the splenii. Use this artwork in gross anatomy and kinesiology modules to teach layered cervical musculature, in physiotherapy and sports medicine materials on cervicogenic headache patterns, and in clinical education illustrating safe surface landmarks for posterior neck examination. It also fits operative anatomy discussions that contrast anterior cervical corridor structures (carotid sheath) with posterior muscular planes. Anatomical accuracy verified by SciePro's Medical Advisory Board.