Middle Scalene Muscle, Posterior View

Description

Posteriorly, the occipital bone and upper cervical spine frame the lateral neck, where the middle scalene (scalenus medius) sits deep to the superficial posterior cervical musculature and runs inferolaterally from the transverse processes of C2 to C7 toward the first rib. Medial to it lies the cervical vertebral column and the nuchal ligament region, while laterally the muscle relates to the posterior triangle of the neck and the superior aspect of the scapular girdle. Inferiorly, the upper thoracic vertebrae and the medial borders of the scapulae provide bony context for the cervicothoracic junction. Depth matters. Clinically, the middle scalene is a key landmark for the interscalene interval, the space between scalenus anterior and scalenus medius that transmits the trunks of the brachial plexus, and its hypertrophy or fibrotic bands can contribute to neurogenic thoracic outlet syndrome with paresthesias and weakness in the upper limb. This posterior-oriented rendering helps clarify why interscalene brachial plexus block targets the plexus at the level of the cricoid cartilage (C6), and why needle trajectory and local anesthetic spread can involve nearby structures at the root of the neck. Understanding its attachment to the first rib also reinforces the muscle’s role as an accessory inspiratory elevator of rib 1 during respiratory distress. Anatomy faculty can slot this into posterior neck dissection labs, regional anesthesia teaching files, and surgical anatomy chapters covering the posterior triangle and brachial plexus exposure near the scalene fat pad. It also fits case-based teaching on thoracic outlet syndrome, cervical radiculopathy differentials, and scapular girdle pain referral patterns in sports medicine and physiotherapy texts. Anatomical accuracy verified by SciePro's Medical Advisory Board.