Superior Serratus Muscle

Description

Posterior thoracic anatomy is presented with the superficial back layers removed to expose the upper ribs, thoracic vertebrae, and medial borders of the scapulae. Deep to the scapula, the superior serratus (serratus posterior superior) sits as a thin quadrilateral sheet running inferolaterally from the lower cervical and upper thoracic spinous processes toward the posterior aspects of ribs 2 to 5, just lateral to the vertebral column. The rhomboid major is also visible, spanning from the spinous processes to the medial scapular border, positioned superficial to the superior serratus and medial to the scapular body. Bony landmarks anchor the relationships. Clinically, this plane matters because serratus posterior superior and the rhomboids are often conflated in posterior shoulder and parascapular pain patterns, yet they occupy different depths and attach to different moving elements (ribs versus scapula). Targeted trigger point injection, dry needling, or surgical exposure near the medial scapular border requires a clear mental map of what lies deep to rhomboid major, where the dorsal scapular nerve and dorsal scapular artery also course along the medial scapular border. Pain from costovertebral and costotransverse joints at ribs 2 to 5 can mimic muscular strain, and this view helps separate joint line tenderness from a true myofascial source. Depth matters. Use this illustration for gross anatomy teaching on posterior thoracic wall layers, for musculoskeletal medicine lectures addressing interscapular pain, and for surgical or sports medicine references discussing the medial scapular approach and dorsal scapular nerve entrapment. It also suits publishing needs for atlas plates that distinguish the serratus posterior superior from the serratus anterior and the rhomboid complex. Anatomical accuracy verified by SciePro's Medical Advisory Board.