Corpus: Nerve to quadratus femoris
1. Definition
The nerve to quadratus femoris is a nerve branch of the sacral plexus.
2. Course
The nerve to the quadratus femoris originates from the ventral branch of the fifth lumbar (L5) and the first and second sacral (S1 and S2) spinal nerves. It may also include fibers from the fourth sacral (S4) nerve. It leaves the pelvis beneath the piriformis muscle through the greater sciatic foramen, and descends anteriorly to the sciatic nerve and alongside the gemelli muscles.
3. Function
The nerve to the quadratus femoris innervates the quadratus femoris muscle and the inferior gemellus muscle. It also sends a small branch to the hip joint.