Lower Extremity

H. Francis Farhadi, Wilson Z. Ray, Sean Barber, Jaime Gasco, and Justin M. Brown

Which spinal nerve roots form the lumbar plexus?

Usually T12-L4 (forming posterior to the psoas muscle)

Which spinal nerve roots form the sacral plexus?

Usually L5-S4 (lying deep in the pelvis)

What are the major nerves given off by the lumbar plexus?

Six major branches:

• Iliohypogastric and ilioinguinal n. (L1)

• Genitofemoral n. (L1–2)

• Femoral n. (L2-L4)

• Lateral femoral cutaneous n. (L2–3)

• Obturator n. (L2-L4)