Serratus posterior superior muscle
The serratus posterior superior is innervated by the anterior primary rami (T2-T5).
- Serratus means saw tooth, in the same way as in serrated knife, referring to the back-and-forth pattern the muscle makes as it attaches to each rib.
- Posterior, meaning on the back side, distinguishes it from the serratus anterior muscle - a similar muscle on the front side of the rib cage.
- Superior distinguishes it from the serratus posterior inferior muscle, which sits below it.