Middle Scalene, Posterior View

Description

Posteriorly oriented on the male neck, the middle scalene (scalenus medius) is highlighted along the lateral cervical column, extending from the posterior tubercles of the transverse processes of C2 to C7 to its insertion on the superior surface of the first rib, posterior to the subclavian groove. Medial to it lie the cervical vertebrae and spinous processes, while the scapulae and upper ribs frame the lower field; the occipital bone and cranial sutures sit superiorly as stable landmarks. The muscle belly occupies the posterolateral neck, where it normally sits posterior to scalenus anterior and anterior to the levator scapulae and upper trapezius fibers. This posterior emphasis matters because the interscalene interval, formed between scalenus anterior and scalenus medius, transmits the roots and trunks of the brachial plexus and the subclavian artery as they pass toward the axilla, and hypertrophy, spasm, or fibrous bands in this region contribute to neurogenic thoracic outlet syndrome. Needle placement for interscalene brachial plexus block and surgical exposure for first rib resection both rely on a clear mental map of how the middle scalene relates to the cervical transverse processes and the first rib. Small distances. High stakes. Use this artwork for gross anatomy teaching of the lateral neck, for anesthesiology and pain medicine lectures on interscalene and supraclavicular approaches, or for surgical and rehabilitation publications discussing thoracic outlet decompression and scalene myofascial pain patterns. Anatomical accuracy verified by SciePro's Medical Advisory Board.