Posterior Superior Serratus, Posterior View

Description

Centered on the upper thoracic back, the serratus posterior superior lies deep to trapezius and the rhomboid major and minor, fanning inferolaterally from the midline toward the posterolateral rib cage. Its thin aponeurosis arises from the nuchal ligament and the spinous processes of C7 to T3, then transitions into fleshy slips that attach along the superior borders of ribs 2 through 5 near their angles. Medial fibers hug the thoracic spinous processes and thoracolumbar fascia, while lateral digitations interdigitate with the external intercostals and sit superficial to the intrinsic back muscles along the costovertebral region. Small, pale tendinous bands highlight the muscle’s attachments against adjacent fascia. Clinically, this layer matters when you need to teach what is removed to reach the posterior thoracic wall: detaching trapezius and rhomboids exposes the serratus posterior superior before the rib angles, intercostal spaces, and paraspinal musculature come into view. Pain along the posterior second to fifth ribs is often attributed to costovertebral dysfunction or myofascial trigger points in this muscle, and palpation is easiest just lateral to the thoracic spinous processes where the slips run obliquely toward the ribs. Respiratory mechanics are the other teaching point, since the muscle is commonly described as an accessory elevator of the upper ribs during deep inspiration, even though its role is modest. Use this posterior female dissection-style view for gross anatomy labs covering the superficial and intermediate extrinsic back muscles, for thoracic wall chapters in medical textbooks, or for rehabilitation and sports medicine materials on upper back pain patterns and rib motion. It also supports surgical education around posterior approaches to the upper ribs and costotransverse region where layering and fascia planes guide safe exposure. Anatomical accuracy verified by SciePro's Medical Advisory Board.