What is the key root level for the femoral nerve?

What is the key root level for the femoral nerve?

• A. L2–L4
• B. L3–L5
• C. L1–L3
• D. L4–L5

Answer: (B)

The femoral nerve comes from the lumbar plexus, formed by the ventral rami of the lower lumbar levels. Its primary root contributions are from L2, L3, and L4, with the nerve arising from the posterior divisions of these roots as it travels under the inguinal ligament to innervate the anterior thigh muscles (including the quadriceps and iliacus) and provide sensory innervation to the anterior thigh and medial leg via the saphenous branch. That makes L2 through L4 the correct root levels. Ranges that omit L2 or L4, or that include L5, don’t match the actual origin of the femoral nerve.

The femoral nerve comes from the lumbar plexus, formed by the ventral rami of the lower lumbar levels. Its primary root contributions are from L2, L3, and L4, with the nerve arising from the posterior divisions of these roots as it travels under the inguinal ligament to innervate the anterior thigh muscles (including the quadriceps and iliacus) and provide sensory innervation to the anterior thigh and medial leg via the saphenous branch. That makes L2 through L4 the correct root levels. Ranges that omit L2 or L4, or that include L5, don’t match the actual origin of the femoral nerve.