Femoral nerve
Nervus femoralis
NervousNervesWhole bodyLeft and right
View left in 3D View right in 3D
- What it is
- The largest branch of the lumbar plexus (L2-L4). It emerges from the lateral border of psoas, runs in the groove between psoas and iliacus, passes under the inguinal ligament just lateral to the femoral artery and within a few centimetres fans out in the femoral triangle; its longest branch, the saphenous nerve, follows the adductor canal to the inner knee and runs down the inner leg to the foot.
- Function
- Motor to iliacus, pectineus, sartorius and the four heads of quadriceps (knee extension); sensation from the front of the thigh and, via the saphenous nerve, the inner leg and foot.
- Size
- About 4 mm thick at the groin; the saphenous nerve ~50 cm long
- Clinical note
- The knee-jerk reflex tests it (L3-L4). A femoral nerve block lateral to the pulse in the groin (order N-A-V: nerve, artery, vein from outside in) relieves the pain of a hip fracture.