Posterior Scalene Muscle, Posterior View

Description

Posterior cervical and upper thoracic musculature is presented in anatomical position, with the trapezius highlighted and spanning from the superior nuchal line and external occipital protuberance down to the spinous processes of the lower cervical and thoracic vertebrae. Deep and lateral to this superficial layer, the posterior scalene (scalenus posterior) occupies the posterolateral neck, running from the transverse processes of C4 to C6 toward its insertion on the second rib, while the levator scapulae and splenius capitis frame it medially and superiorly. Midline landmarks such as the nuchal ligament, cervical spinous processes, and the medial borders of the scapulae establish orientation, with the deltoid and other shoulder girdle fibers appearing laterally at the proximal humerus. Fiber direction matters. A posterior view is often the clearest way to teach how the superficial trapezius can obscure deeper lateral neck muscles, including the posterior scalene, and why careful layer-by-layer exposure is required during posterior cervical approaches and selective neck dissection. Clinically, the scalene interval relates directly to thoracic outlet syndrome, where brachial plexus roots and the subclavian artery can be compressed between scalenus anterior and medius, while hypertrophy or anomalous bands near scalenus posterior can alter the mechanics of first and second rib elevation during forced inspiration. Trapezius integrity also matters: spinal accessory nerve injury produces shoulder droop and impaired scapular upward rotation, findings that are easier to correlate when you can map the muscle back to its cervical and thoracic attachments. Use this plate in gross anatomy teaching for the posterior triangle and posterior cervical musculature, in physical therapy materials on scapulothoracic rhythm and accessory nerve palsy, or in surgical education when illustrating planes of dissection from trapezius to deeper cervical musculature and rib attachments. Anatomical accuracy verified by SciePro's Medical Advisory Board.