Splenius Cervicis, Posterior View

Description

Posteriorly, the splenius cervicis lies deep to the trapezius and splenius capitis, forming paired, oblique muscle bellies on either side of the midline from the upper thoracic spinous processes toward the cervical transverse processes. Its fascicles course superolaterally, sitting lateral to the cervical spinous processes and medial to the posterior border of the sternocleidomastoid’s lateral neck contour (not seen from this view). Surrounding bony landmarks in this upper back field typically include the occiput superiorly, the cervical and upper thoracic vertebrae centrally, and the scapulae and proximal humeri laterally. Bilateral symmetry is clear. Clinically, this layer matters because the splenius cervicis is a frequent pain generator in posterior cervical myofascial syndromes, with trigger points referring discomfort to the lateral neck and occipital region and often misattributed to facet arthropathy. Its line of pull explains why unilateral hypertonicity can contribute to ipsilateral neck rotation and lateral flexion, a pattern commonly encountered after whiplash-type acceleration injuries. For procedural anatomy, recognizing what sits superficial (trapezius) and what sits deep (splenius cervicis, semispinalis cervicis) helps frame safe trajectories for posterior cervical injections and guides dissection plans when reflecting the superficial back muscles from the nuchal region. Educators can place this view directly into gross anatomy lab guides for the posterior neck, pairing it with segmental innervation (dorsal rami of cervical spinal nerves) and actions during resisted extension and rotation testing. Publishers often need this specific perspective to clarify layered relationships during surgical exposures of the posterior cervical spine and in rehabilitation texts discussing cervicogenic headache and scapulocervical muscle imbalance. Anatomical accuracy verified by SciePro's Medical Advisory Board.