Femoral nerve (L2–L4)
Nerves · L2 L3 L4
Largest branch of the lumbar plexus. Emerges from the lateral border of psoas, descends in the groove between psoas and iliacus and enters the thigh deep to the inguinal ligament lateral to the femoral artery and OUTSIDE the femoral sheath, then divides in the femoral triangle.
Traced from the start
Detail
- Motor
- Iliacus (in the abdomen), pectineus, sartorius, quadriceps femoris
- Sensory
- Anterior and medial thigh (anterior cutaneous branches); medial leg and foot via the saphenous nerve
- Reflex
- Knee jerk (L3–L4)
- At the groin
- NAVEL from lateral to medial — the nerve is the most lateral structure, outside the sheath
When it goes wrong
Iliacus or psoas haematoma (anticoagulation, haemophilia), retractor pressure in pelvic surgery, prolonged lithotomy, or diabetic amyotrophy
Weak hip flexion and knee extension with a buckling knee, absent knee jerk, numb anterior thigh and medial leg; hip adduction is spared (obturator)
Practise this structure
1 question in the bank tagged Femoral Nerve.