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Elbow

Cubital Tunnel Syndrome: the other pinched nerve.

Compression of the ulnar nerve at the elbow, the 'funny bone' nerve, causing numbness in the ring and small fingers. It is the second most common nerve compression in the arm after carpal tunnel, and many cases improve without surgery.

Written bySteven J. Lee, MD · Chief of Hand and Upper Extremity Surgery, Lenox Hill Hospital
Last reviewed · May 2026

Cubital tunnel syndrome is compression or irritation of the ulnar nerve as it passes behind the inside of the elbow. Bending the elbow stretches and tightens the space around the nerve, which is why symptoms are often worst at night or when the elbow is held flexed, like holding a phone.

Most patients notice numbness and tingling in the ring and small fingers. When compression is more advanced, the hand can become weak or clumsy, and in long-standing cases the small muscles of the hand can atrophy. Catching it before that point matters.

Symptoms

Typical complaints include:

  • Numbness and tingling in the ring and small fingers
  • Symptoms worse with the elbow bent or leaning on the inside part of the elbow
  • Aching on the inside of the elbow
  • Weak grip, dropping things, or clumsiness in advanced cases
  • Difficulty spreading the fingers if the nerve is severely affected

How it is diagnosed

Diagnosis combines the history and exam with a nerve test (EMG and nerve conduction study) that measures how well the ulnar nerve is working across the elbow. The test also helps grade severity and guide whether surgery is warranted.

Dr. Lee's approach

Most cubital tunnel cases respond to non-surgical care. Dr. Lee starts with activity changes, avoiding prolonged elbow flexion, a nighttime splint that keeps the elbow relatively straight, and avoidance of leaning on the inside part of the elbow.

Surgery is considered when symptoms persist despite these measures, when there is muscle weakness, or when the nerve test shows meaningful damage. The procedure releases the tight structures around the nerve, and in some cases moves the nerve to a less exposed position. Delaying surgery in the presence of weakness or wasting can limit recovery, so timing matters.

Non-surgical treatment

Most patients start, and stay, here:

  • A nighttime splint that keeps the elbow from bending fully
  • Activity modification to reduce prolonged or repetitive elbow flexion
  • Avoidance of pressure on the inside of the elbow
  • Padding the inside of the elbow to limit direct pressure on the nerve

Surgical treatment

When conservative care fails or weakness is present, the nerve is decompressed by releasing the tight tissue over it. Depending on the situation, the nerve may be left in place (in situ decompression) or moved in front of the elbow (transposition). The choice depends on the anatomy and whether the nerve is unstable.

Recovery timeline

Recovery after surgery is usually straightforward:

  1. Day 0 to 7
    Soft dressing or light splint. Move the fingers immediately. Keep the wound dry until the first visit.
  2. Weeks 1 to 4
    If transposition is chosen, a splint may be worn for 3-4 weeks. Begin gentle elbow motion. Numbness often improves first; strength recovers more gradually.
  3. Weeks 4 to 12
    Progressive strengthening and return to activity. Nerve recovery can continue for months, especially in long-standing cases.

What patients commonly misunderstand

Two things to clear up:

  • It is not carpal tunnel. Carpal tunnel affects the median nerve at the wrist (thumb-side fingers). Cubital tunnel affects the ulnar nerve at the elbow (ring and small fingers). The treatments are different, so the right diagnosis matters.
  • Do not wait for weakness. Severe or long-standing compression can leave permanent numbness or muscle wasting even after a good operation. Persistent symptoms, especially with any weakness, are a reason to be evaluated rather than wait.

This page is general educational content authored by Dr. Lee. It is not a substitute for individual medical advice. Every patient's case is different, book a consultation to discuss yours.

Patient questions

Cubital tunnel, answered.

  • Why do my ring and small fingers go numb?

    Those fingers are supplied by the ulnar nerve, which runs behind the inside of the elbow through the cubital tunnel. When the nerve is compressed or irritated there, often made worse by keeping the elbow bent, the result is numbness and tingling in the ring and small fingers, sometimes with aching at the elbow. Eventually weakness of the fingers occurs.

  • Will I need surgery?

    Most people do not. Most cases improve with a nighttime splint that keeps the elbow from bending fully, along with activity changes. Surgery is considered when symptoms persist despite these measures, when there is weakness of the fingers, or when nerve testing shows meaningful damage.

  • What does the surgery involve?

    The tight tissue compressing the ulnar nerve is released. Depending on the anatomy and whether the nerve is stable, it is either left in place or moved to the front of the elbow. Numbness often begins improving first, with strength returning more gradually over weeks to months.

Next step

Numb fingers and an achy elbow? It is usually very manageable.

Cubital tunnel syndrome is common and most cases settle with simple measures. The reason to be evaluated is to confirm the diagnosis and to treat it before weakness or muscle wasting develops, since those are harder to reverse.