Posterior Superior Serratus Muscle

Description

Running obliquely from the upper thoracic spinous processes to the posterior aspects of the upper ribs, the serratus posterior superior sits deep to the trapezius and rhomboid muscles and superficial to the erector spinae. Its thin, quadrilateral muscle belly arises from the nuchal ligament and the spinous processes of C7 to T3 (variable) and inserts via digitations onto ribs 2 to 5 near their angles, lateral to the vertebral column. A posterior view also logically includes the cervical and upper thoracic vertebrae, posterior ribs, scapulae, and the overlying trapezius spanning from the midline to the acromial region. Relationships matter here: the serratus posterior superior lies medial to the scapular borders, inferior to the nuchal region, and superior to the serratus posterior inferior. Clinically, this muscle is a frequent source of diagnostic noise when evaluating posterior thoracic pain because its attachments near the rib angles can mimic costovertebral joint dysfunction or intercostal strain. Palpation and trigger-point referral patterns in the upper back, often perceived around the scapular medial border and posterior ribs, are easier to teach when the rib insertions are clearly mapped to the thoracic spine. Surgeons approaching the posterior thoracic wall and anesthetists planning regional techniques also benefit from understanding which muscular layers must be traversed to reach the ribs and paravertebral space. Small muscle. Common confusion. Ideal for gross anatomy, kinesiology, and musculoskeletal medicine teaching when you need a clean posterior thoracic wall reference that distinguishes superficial scapulothoracic musculature from deeper rib elevators. It also supports figure-based explanations in textbooks and patient education on upper back pain generators and rib angle landmarks. Anatomical accuracy verified by SciePro's Medical Advisory Board.