The sciatic nerve is the key nerve of the lumbosacral
plexus. It arises from the spinal nerves of L4 through S3. The sciatic nerve is
the cornerstone of the lumbosacral plexus. Knowledge of the lumbosacral plexus
starts with the sciatic nerve because it is the most important nerve. The
lumbosacral plexus is comprised of the sciatic nerve and S4. The branches of
the lumbosacral plexus are the superior gluteal nerve (L4-S1), the inferior gluteal
nerve (L5-S2), the posterior cutaneous nerve of the thigh (S1-S3), and the
pudendal nerve (S2-S4) (SIPP).
