The sciatic nerve - also known as the ischiadic nerve - is a large nerve arising from the sacral plexus that innervates the muscles of the pelvis and thigh.

This nerve originates from the ventral branches (anterior rami) of the fourth and fifth lumbar nerves (L4 - L5) and first three sacral nerves (S1 - S3).

The sciatic nerve exits the pelvic cavity via the infrapiriform foramen and then descends along the posterior surface of the obturator internus muscle, superior gemellus muscle, inferior gemellus muscle and quadratus femoris muscle. Further, the nerve passes between the muscles of the posterior group of the thigh and the adductor magnus muscle.

Upon reaching the upper part of the popliteal fossa, the sciatic nerve splits into two terminal branches - the tibial nerve and common peroneal (fibular) nerve.

On its course, the sciatic nerve gives off several motor branches that supply the muscles of the pelvic girdle - internal obturator, superior gemellus, inferior gemellus, quadratus femoris, and muscles of the thigh, including the posterior thigh muscles (biceps femoris muscle, semitendinosus muscle, semimembranosus muscle), and the adductor magnus.

Unlock with Premium

Sciatic nerve