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Definition

The peroneal nerve is on the outer part of the lower knee. This nerve sends impulses to and from the leg, foot, and toes. If it is damaged, the muscles may get weak and feeling may be lost. Foot drop may happen. This is when you can’t raise the foot.

Causes

This injury is often caused by an injury to the leg.

This can happen with:

  • A broken leg bone
  • A knee injury
  • Surgery to the leg or knee
  • Ankle injuries
Peroneal Nerve Damage After Ankle Injury and Repair
Peroneal injury
Copyright © Nucleus Medical Media, Inc.

Too much pressure on the nerve can happen with:

  • Sitting position
  • Cast on lower leg, mostly if it is too tight
  • Blood clots, tumors, or other masses

Risk Factors

Your risk may be raised with:

  • Recent trauma to the leg
  • Having a cast on your leg
  • Too much sitting with your legs crossed
  • Being on bedrest
  • Being very thin

Symptoms

You may have:

  • Numbness or a feeling of pins and needles in the lower leg
  • Pain in foot or shin
  • A week foot
  • Prickling feeling

Diagnosis

Your doctor will ask about your symptoms and health history. A physical exam will be done. An part of your exam will be checking how well your nerves and muscles are working in your leg. Your doctor may want to watch you as you walk.

You may need:

Treatment

Talk with your doctor about the best plan for you. You may have:

Physical Therapy

A therapist will work with you to strengthen your leg and foot muscles.

Orthotics

An ankle and foot brace is used to treat foot drop.

Surgery

In some cases, surgery is done. This involves taking pressure off the nerve.

Prevention

To lower your chance of a peroneal nerve injury:

  • Avoid crossing your legs.
  • Move around often.
  • If you work on your knees, wear equipment to protect them.
  • If you have a cast on your leg, let your doctor know right away if you are having numbness or tingling.

RESOURCES

National Institute of Neurological Disorders and Stroke  http://www.ninds.nih.gov 

Ortho Info—American Academy of Orthopaedic Surgeons  http://orthoinfo.org 

CANADIAN RESOURCES

The Canadian Orthopaedic Association  http://www.coa-aco.org 

Health Canada  https://www.canada.ca 

References

Mononeuropathies. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/neurologic-disorders/peripheral-nervous-system-and-motor-unit-disorders/mononeuropathies. Updated September 2016. Accessed June 23, 2018.

NINDS foot drop information page. National Institute of Neurological Disorders and Stroke website. Available at: https://www.ninds.nih.gov/Disorders/All-Disorders/Foot-Drop-Information-Page. Accessed June 23, 2018.

Stewart JD. Foot drop: where, why and what to do? Pract Neurol. 2008;8(3):158-169.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 05/2018
  • Update Date: 06/23/2018