Splenius Cervicis

Description

Arising from the spinous processes of the upper thoracic vertebrae (typically T3 to T6), the splenius cervicis is shown as a paired, obliquely oriented posterior neck muscle that ascends superolaterally to insert on the posterior tubercles of the transverse processes of C1 to C3. Superior to it, the splenius capitis occupies a more cranial position as it fans toward the mastoid region and superior nuchal line. Deep to the splenius layer, the cervical spinous processes align in the midline, while the scapulae sit inferolaterally on the posterior thorax with the upper ribs and costal angles partly exposed. Functionally, splenius cervicis contributes to ipsilateral rotation and lateral flexion of the cervical spine, and bilaterally it assists cervical extension, a relationship that is clearer from a posterior perspective where fiber direction and segmental attachments read cleanly. Palpation and pain referral in this region are often discussed in the context of cervicogenic headache and posterior neck myofascial pain, and the splenius plane also matters when teaching safe depth for posterior cervical injections and when distinguishing superficial extensors from deeper transversospinalis muscles. Orientation matters. Confusing splenius cervicis with sternocleidomastoid is a common learner error because SCM dominates the lateral neck in anterior and lateral views, yet it does not occupy the posterior midline field shown here. Use this plate in gross anatomy and kinesiology courses to teach layered posterior neck musculature, and in spine or rehabilitation texts to support explanations of rotational mechanics and common extension related strain patterns at the cervicothoracic junction. It also suits clinical education materials for physical therapy, sports medicine, and pain clinics where clear landmarks relative to C1 to C3 and the upper thoracic spinous processes are required. Anatomical accuracy verified by SciePro's Medical Advisory Board.