Serratus Posterior Superior
Serratus posterior superior attaches to C6-T3 and inserts on ribs 2-5, trapping the 2nd and 3rd thoracic vertebrae. There is a thin sheet of connective tissue that continues from the short bellies of the muscle on the rib to the supraspinous ligament over the spinous process. The width of this aponeurosis varies significantly among dissections but tends to be a much larger part of the structure than is usually illustrated. This muscle is the most superficial of the intrinsic back muscles and straps across the erectors, levator costae, and intrinsic spine muscles.
This muscle acts as a 5th scalene in elevating the ribs for inhalation, especially when the person is bent forward, as when working on a laptop while reclining on a couch.
Origin – nuchal ligament from about C6 and along the supraspinous ligament and spinous processes from C7 to T2 or T3.
Insertion – superior aspect of ribs 2-5, just lateral to the angle of the rib
Function – elevation of the ribs, assists in inhalation
Tony Preston has a practice in Atlanta, Georgia where he sees clients.
He has written and taught about anatomy, trigger points and cranial therapies since the mid-90s.