Femoral Nerve

What is the femoral nerve?

The femoral nerve is one of the largest nerves in the leg. It has a motor function to help you move your hips, legs, ankles and feet. It also has a sensory function, helping you feel touch, pain and hot or cold temperatures.

The femoral nerve is part of the peripheral nervous system. This system sends signals from your brain to the lower limbs, upper limbs and some organs.

What is the purpose of the femoral nerve?

The femoral nerve is one of two major nerves that provide motor (movement) and sensory functions to the lower limbs. The femoral nerve is for the front of the leg, while the sciatic nerve serves the back of the leg.

The femoral nerve:

• Stimulates thigh and hip flexor muscles (the psoas major and iliacus muscles) to help you bend and straighten your legs and knees and bend at the hip.
• Provides touch, pain and temperature sensations to the hip, thigh, knee and leg.

Where is the femoral nerve?

The femoral nerve:

• Originates from L2 to L4 nerve roots in the lumbar plexus.
• Enters the femoral triangle, a hollow, wedge-shaped area between the upper thigh and groin. The femoral nerve, femoral artery, femoral vein and lymphatic vessels go through this triangle.
• Runs down the front of the thigh between the psoas major and hip flexor muscles.
• Travels alongside the femoral artery, the large blood vessel that carries blood to the lower limbs.
• Splits into two nerves, anterior and posterior division, beneath the inguinal ligament.
• The posterior division becomes the saphenous nerve at the adductor canal, a narrow tunnel-like opening in the thigh. The saphenous nerve provides sensations to the knee, lower leg, ankle and foot.

What are the femoral nerve branches?

Near the pubic bone, the femoral nerve branches into the anterior (superficial) femoral nerve and the posterior (deep) femoral nerve. Each of these branches provide certain motor or sensory functions:

• Sensory functions: The anterior femoral nerve provides sensory functions to the front and middle part of your thigh. The posterior femoral nerve becomes the saphenous nerve, which provides sensory information to your lower leg and foot.
• Motor functions: The anterior femoral branch helps you flex and move at the hips. The posterior femoral branch controls your quadriceps muscles to help straighten your knees.

What conditions and disorders affect the femoral nerve?

Conditions that damage or affect the femoral nerve include:

• Femoral nerve neuropathy (femoral nerve dysfunction): Neuropathy is another word for nerve damage. Damage that affects only one femoral nerve is known as mononeuropathy.
• Meralgia paresthetica: Pressure on the lateral femoral cutaneous nerve in the thigh causes meralgia paresthetica. It’s a type of painful nerve compression syndrome.
• Pinched nerve: Swollen tissues squeeze the nerve, causing a pinched nerve or nerve entrapment.

What causes femoral nerve problems?

Wearing tight clothing or a heavy toolbelt around the waist can lead to lateral femoral cutaneous nerve problems. Other possible causes include:

• Accidents and trauma.
• Broken leg, broken hip or pressure from a cast or splint.
• Complications from surgeries, such as hip replacement or hysterectomy, or from femoral artery catheterization procedures.
• Diabetes.
• Herniated disk.
• Infections.
• Prolonged pressure on the nerve, sometimes from pregnancy or obesity.
• Radiation therapy.
• Tumors, cysts or hematomas (blood that leaks outside of blood vessels under the skin).

What are the signs of femoral nerve problems?

Pain that radiates from your back and hips into your legs (radicular pain) is a common sign of femoral nerve damage. Other symptoms include:

• Leg, ankle or foot numbness, weakness, tingling, paralysis or pain.
• Lower back pain, hip pain or groin pain.
• Difficulty straightening the knee, leg or ankle.
• Muscle loss in the legs.
• Problems walking.

How are femoral nerve problems diagnosed?

Your healthcare provider will perform a physical exam and evaluate your symptoms. Your provider may also order one or more of these tests to make a diagnosis:

• Electromyography and nerve conduction study to measure electrical signals sent through the nervous system.
• MRI or X-rays to look for broken bones, tumors and muscle damage.
• Neuromuscular ultrasound to check for inflammation, tumors and nerve damage.

What is the role of the femoral nerve in the knee-jerk reflex?

A knee-jerk reflex test is often part of a standard physical exam. Healthcare providers perform this simple test to check for signs of potential peripheral nerve damage.

During the test:

• Your provider gently taps on the patellar tendon below the kneecap with a soft rubber mallet.
• The tap causes the femoral nerve to send a message to the spine.
• Your lower leg kicks out a little.

This reflex is known as the Westphal sign. If there’s little or no reaction, you may have a pinched nerve or nerve damage.

How are femoral nerve problems treated?

Treatments for femoral nerve problems include:

• Nerve block to inject a numbing agent (anesthetic) around the nerve that temporarily stops the nerve from sending pain signals to the brain. You may need this treatment while recovering from a broken hip or hip replacement. Healthcare providers also use femoral nerve blocks to numb the leg during knee surgery.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) and steroid injections to ease nerve inflammation and pain.
• Physical therapy to improve flexibility and range of motion in the hips, legs and knees.
• Splints or casts to support the leg and hip, taking pressure off the nerve.
• Surgery to remove a tumor or repair or replace a damaged nerve (nerve transfer).

How can I protect my femoral nerves?

These steps can keep your nervous system healthy:

• Adopt healthy ways to manage stress like meditation, walking or listening to music.
• Be physically active most days of the week.
• Eat a nutritious diet.
• Get enough sleep.
• Lose excess weight (if needed).
• Manage conditions like diabetes and high blood pressure that cause neuropathies.
• Seek help to quit smoking. Tobacco slows blood flow to the nerves.

When should I talk to a doctor?

You should call your healthcare provider if you experience:

• Difficulty walking.
• Inability to bend or straighten the knees or flex the ankles.
• Pain, numbness or weakness in the legs or feet.

A note from Cleveland Clinic

The femoral nerves help you bend and straighten your hips and legs. The nerves also send sensations from the leg to the brain. Healthcare providers sometimes use femoral nerve blocks to ease pain in people recovering from broken knees or knee replacement surgery. Trauma, surgery or constriction (tightness) near the nerve can damage the femoral nerves, leading to pain, weakness or numbness. A pinched nerve or herniated disk in the lumbar region can also cause nerve pain. See your provider if you have pain in your legs or trouble walking — they can find the source and offer solutions.