Trapezius Muscle Under the Skin, Posterior View

Description

Running obliquely from the superior nuchal line and external occipital protuberance down to the spinous processes of C7 through T12, the trapezius forms a broad superficial sheet across the posterior neck and thorax. Its upper fibers descend to the lateral third of the clavicle, middle fibers run transversely to the acromion and spine of the scapula, and lower fibers ascend toward the medial end of the scapular spine, framing the scapulae on either side of the vertebral column. Beneath the trapezius, rhomboid minor and major occupy the medial scapular border from the nuchal ligament and upper thoracic spines, while the superior margin of latissimus dorsi enters inferiorly as the back widens toward the flank. Clinically, a posterior surface view like this clarifies why the spinal accessory nerve (CN XI) is so vulnerable: after traversing the posterior cervical triangle it supplies the deep surface of trapezius, and iatrogenic injury during lymph node biopsy can leave a drooping shoulder, impaired scapular upward rotation, and difficulty abducting the arm above 90 degrees. Fiber direction also matters in rehabilitation, because upper trapezius dominance can mask lower trapezius weakness in scapular dyskinesis and contribute to cervicogenic headache patterns. Palpation landmarks are clear. The acromion, scapular spine, and midline nuchal region. Use this artwork in gross anatomy and kinesiology teaching to connect attachments to actions (elevation, retraction, and depression of the scapula) and to contrast trapezius with rhomboids during scapular setting drills. It also fits orthopedic and sports medicine publications on shoulder impingement and postoperative neck dissection complications, where recognizing trapezius contour under the skin supports both exam documentation and patient education. Anatomical accuracy verified by SciePro's Medical Advisory Board.