Posterior Perspective of the Middle Scalene

Description

Arising from the posterior tubercles of the cervical transverse processes (classically C2 to C7), the middle scalene (scalenus medius) descends inferolaterally toward its broad insertion on the superior surface of the first rib, posterior to the scalene tubercle. From a posterior neck perspective, it sits lateral to the cervical vertebrae and deep to the more superficial posterior cervical musculature, with the semispinalis capitis positioned medial and posterior as it spans from the upper thoracic and lower cervical region to the occipital bone. Superiorly, the occipital squama and nuchal region frame the upper limit of the field, while the scapulae appear inferolaterally as bony landmarks for the shoulder girdle. Deep planes matter here. Clinically, scalenus medius defines the posterior boundary of the interscalene interval, the corridor used for an interscalene brachial plexus block, so its fiber direction and depth relative to the cervical transverse processes help explain needle trajectory and common pitfalls. The dorsal scapular nerve commonly pierces the middle scalene, and irritation at this passage can refer pain along the medial scapular border and complicate the differential for cervical radiculopathy. Hypertrophy or spasm of the scalene group can contribute to neurogenic thoracic outlet symptoms, even when the patient’s primary complaint feels posterior and periscapular. Use this posterior-focused rendering when teaching cervical muscle layers in gross anatomy, kinesiology, or regional anesthesia modules, and when illustrating manuscripts on thoracic outlet syndrome, scalene myofascial pain patterns, or approaches to the cervical transverse processes as procedural landmarks. It also fits well in spine and pain clinic patient education where a back-of-neck viewpoint matches what patients palpate. Anatomical accuracy verified by SciePro's Medical Advisory Board.