Nerve
Femoral nerve
Lumbar-plexus nerve supplying knee extension and anterior thigh sensation
High-yield
Near the inguinal ligament, the femoral nerve lies lateral to the femoral artery. It carries both limbs of the patellar reflex pathway, linking quadriceps stretch to knee extension.
Overview
The femoral nerve forms within the psoas region and reaches the thigh beneath the inguinal ligament. Its muscular branches supply the quadriceps and several hip-flexing muscles, while cutaneous branches serve the anterior thigh and continue medially down the leg through the saphenous nerve.
Reference facts
- Root value
- Posterior divisions of the L2–L4 ventral rami in the lumbar plexus
- Course
- Emerges at the lateral psoas border, runs between psoas and iliacus and passes beneath the inguinal ligament lateral to the femoral artery before branching in the thigh
- Motor
- Quadriceps femoris, sartorius, iliacus and usually pectineus; psoas major receives direct lumbar branches
- Sensory
- Anterior and anteromedial thigh through cutaneous branches; medial leg and part of the medial foot through the saphenous nerve; articular branches to hip and knee
Clinical correlation
Femoral neuropathy can weaken knee extension, make the knee buckle and reduce the patellar reflex. A partial injury need not abolish the reflex, and a reduced reflex can also result from an L2–L4 root or other neurological problem.
Frequently asked questions
What are the roots of the femoral nerve?
Posterior divisions of the L2–L4 ventral rami in the lumbar plexus.
What muscles does the femoral nerve supply?
Quadriceps femoris, sartorius, iliacus and usually pectineus; psoas major receives direct lumbar branches.
What is the sensory distribution of the femoral nerve?
Anterior and anteromedial thigh through cutaneous branches; medial leg and part of the medial foot through the saphenous nerve; articular branches to hip and knee.
What is the course of the femoral nerve?
Emerges at the lateral psoas border, runs between psoas and iliacus and passes beneath the inguinal ligament lateral to the femoral artery before branching in the thigh.