Nerve compression in the leg and foot: an overview

What a compression neuropathy is

Nerves run through narrow passages between muscles, bones and bands of connective tissue. If the passage becomes tight, or the nerve is pressed from outside, the nerve’s blood supply and signal can be disrupted. This produces tingling, numbness, burning or aching pain, and sometimes weakness. The condition can be just as disabling in the leg as compression neuropathies of the wrist and elbow are in the arm.^[1]

Problems at these sites are frequently overlooked or mistaken for other things. Tunnel syndromes of the foot and ankle are underrecognized and often misdiagnosed.^[3]

Common sites in the lower limb

• Lateral femoral cutaneous nerve: burning or numbness on the outer thigh
• Common peroneal nerve: numbness on the outer leg and top of the foot, and sometimes weak foot lift
• Saphenous nerve: pain or numbness along the inner leg
• Sural nerve: burning or numbness along the outer foot and ankle
• Tibial nerve and its branches: burning and tingling behind the inner ankle and in the sole

These are the lower-limb sites described most often in the literature.^[1,2] In the foot and ankle, tunnel syndromes involve the sural nerve, the deep peroneal nerve, the tibial nerve, the medial plantar nerve and the inferior calcaneal nerve.^[3] Learn more about the most frequent ones:

• Common peroneal nerve compression
• Tarsal tunnel syndrome
• Anterior tarsal tunnel syndrome
• Superficial peroneal nerve entrapment
• Baxter’s nerve entrapment
• Morton’s neuroma
• Other foot and ankle nerve entrapments

What causes them

Tunnel syndromes in the foot and ankle can result from trauma, anatomical variations, repetitive strain and systemic conditions.^[3] Entrapment neuropathies are also seen in people with certain rheumatological and systemic disorders.^[2] Practical contributors include tight footwear, a cast or brace, prolonged awkward positions, swelling, cysts or bone spurs, scar tissue after surgery, and a previous injury.

How they are diagnosed

Entrapment neuropathies can be told apart from other causes of leg pain by identifying a characteristic pattern of weakness or sensory loss. A focused bedside neurological examination is key.^[2] Accurate diagnosis relies on a detailed history and examination, with electrodiagnostic tests and imaging as adjuncts.^[3] Nerve studies and imaging are arranged with another specialist. See nerve testing for foot pain. Because a pinched nerve in the back and a body-wide neuropathy can look similar, they also need to be considered: back or foot? and peripheral neuropathy.

Treatment

Treatment follows the cause and how severe the compression is:

• Conservative care, including physical therapy, orthotics and corticosteroid injections, is often effective.^[3] See non-surgical treatment.
• Surgical decompression is reserved for cases that do not respond.^[3] See nerve decompression.
• If a nerve is damaged or cut, repair, grafting or transfer may be considered. See nerve repair, nerve grafting and nerve transfer.
• If surgery has been done and symptoms return, see revision nerve surgery.

Timely intervention, whether conservative or surgical, is important for relieving symptoms and restoring function.^[3]

When to seek care

Consider an evaluation if you have burning, tingling, numbness or weakness in the leg or foot that follows a nerve path, or has lasted more than a few weeks.