The Femoral Nerve

Overview

• Nerve roots: L2-L4
• Motor functions: Innervates the anterior thigh muscles that flex the hip joint (pectineus, iliacus, sartorius) and extend the knee (quadriceps femoris: rectus femoris, vastus lateralis, vastus medialis and vastus intermedius),
• Sensory functions: Supplies cutaneous branches to the anteromedial thigh (anterior cutaneous branches of the femoral nerve) and the medial side of the leg and foot (saphenous nerve).

By TeachMeSeries Ltd (2025)

Fig 1
Derivation of the femoral nerve from the lumbar plexus.

Pro Feature - Dissection Images

You've Discovered a Pro Feature

Access our Dissection Image Library

Enhance your understanding with high-resolution dissection images showcasing real-life anatomy.

Learn More

Anatomical Course

The femoral nerve is the largest branch of the lumbar plexus. It is derived from the anterior rami of nerve roots L2, L3 and L4.

After arising from the lumbar plexus, the femoral nerve travels inferiorly through the psoas major muscle of the posterior abdominal wall. It supplies branches to the iliacus and pectineus muscles prior to entering the thigh.

The femoral nerve then passes underneath the inguinal ligament to enter the femoral triangle. Within this triangle, the nerve is located lateral to the femoral vessels (unlike the nerve, the femoral artery and vein are enclosed within the femoral sheath).

Approximately 4cm below the inguinal ligament, the femoral nerve divides into anterior and posterior divisions:

The terminal cutaneous branch of the femoral nerve is the saphenous nerve. It travels through the adductor canal (accompanied by the femoral artery and vein) and exits prior to the adductor hiatus. The saphenous nerve innervates the medial aspect of the leg and the foot.

By TeachMeSeries Ltd (2025)

Fig 2
Anatomical course of the femoral nerve and its two cutaneous branches – anterior cutaneous fibres and saphenous nerve.

Motor Functions

The femoral nerve supplies the muscles of the anterior thigh:

• Hip flexors:
  • Pectineus – adducts and flexes the thigh, assists with medial rotation of the thigh.
  • Iliacus – acts with psoas major and psoas minor (forming iliopsoas) to flex the thigh at the hip joint and stabilise the hip joint.
  • Sartorius – flexes, abducts and laterally rotates the thigh at the hip joint. Flexes the leg at the knee joint.
• Knee extensors:
  • Quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis and vastus intermedius) – extends the leg at the knee joint. Rectus femoris also steadies the hip joint and assists iliopsoas in flexing the thigh.

By TeachMeSeries Ltd (2025)

Fig 3
The muscles of the anterior thigh.

Sensory Functions

There are two main sensory branches that arise from the femoral nerve:

• Anterior cutaneous branches – derived from the anterior division of the femoral nerve. They supply the skin of the anteromedial thigh.
• Saphenous nerve – a continuation of the posterior division of the femoral nerve. It supplies the skin of the medial leg and foot.

By TeachMeSeries Ltd (2025)

Fig 4
The cutaneous innervation of the branches of the femoral nerve.