The serratus posterior superior is one of the two muscles within the intermediate group of extrinsic back muscles, the other being the serratus posterior inferior. It is a thin, rectangular shaped muscle which les just deep to the rhomboid major and rhomboid minor. These two thin muscles lie deep to the superficial extrinsic muscles.
Origin
- Ligamentum nuchae
- Spinous processes of C7-T3
- Supraspinous ligaments
Insertion
- Superior edgeof ribs 2-5 (lateral to their angles)
Action
- Elevates ribs 2-5
Innervation
- Anterior rami of upper thoracic nerves: T2-T5
Blood Supply
- Intercostal arteries