Ulnar Nerve Entrapment

Medically Reviewed by Tyler Wheeler, MD on August 12, 2022
6 min read

Ulnar nerve entrapment is when too much pressure is put against a nerve in your elbow by bones, tendons, muscles, or cartilage and it becomes inflamed or swollen. It’s also known as cubital tunnel syndrome.

A pinched nerve can start in several places throughout your body, but usually in the joints. When a pinched nerve is in your elbow, it can leave your arm and hand, especially the ring finger and pinky, feeling sore, numb, or weak.

The ulnar nerve runs the length of your arm. It helps control the muscles in the forearm and hand. Sensations affecting your ring finger and little finger also travel through the ulnar nerve. Its most vulnerable point is at the elbow.

If you’ve ever hit your elbow, or “funny bone,” hard and felt a tingling down to your fingers, you’ve compressed your ulnar nerve.

Leaning on your elbow for a long time can also irritate the nerve. Whenever you bend your elbow, you’re forcing the nerve to stretch around the bones in the joint. If you sleep with your elbows bent, for instance, or you keep your elbows bent for a long time, you’re putting more pressure on your ulnar nerve.

The reasons for compression of the ulnar nerve aren’t always known. You may not remember injuring your elbow or bending your elbow too much, but a few things can lead to ulnar nerve entrapment, including:

Inflammation and a buildup of fluid in the sac between your elbow bone and skin, a condition called bursitis

Your chances of getting ulnar nerve entrapment are also higher if:

One of the first signs that you may have a pinched nerve in the elbow is weakness in your hand. You may not be able to grip things as tightly as you used to, and you may find it harder to lift heavy things.

Your hand may be more tender and more easily hurt. The ring finger and little finger may not be as strong and flexible as they used to be.

  • Other symptoms of ulnar nerve entrapment include:
  • Feeling of “falling asleep” (tingling or numbness) in your hand, especially your ring and little fingers
  • Cold sensitivity in the affected arm or hand
  • Tenderness at your elbow
  • A hard time doing precise things with your fingers, like sewing or playing an instrument
  • Deformity or unusual shape of your ring and little fingers

These symptoms tend to come and go at first. You may notice some symptoms more when your elbow is bent. You may even wake up in the middle of the night with a tingling feeling in your fingers.

If a pinched nerve in the elbow goes untreated for a long time, there could be permanent damage.

Muscles controlled by the nerve may begin to get smaller and shorter. This is called muscle wasting, and it can’t always be reversed.

To avoid this problem, see a doctor quickly if you start to have serious pain, weakness, or tingling in your arm or hand. Even if your discomfort doesn’t feel serious, call your doctor if it’s been with you for at least 6 weeks.

To get a proper diagnosis, you should see an orthopedist. Try to find someone who specializes in elbows and wrists.

If you have arthritis and you see a rheumatologist, you may want to start with that doctor. They may later recommend you to an orthopedist. What you might expect:

  • Medical review: Diagnosing the problem usually starts with a review of your medical history and your lifestyle. If you do a lot of heavy lifting or play contact sports, these would be helpful details to pass along.
  • Physical exam: Your doctor will likely do a physical exam of your arm, tapping the spot where the nerve crosses the bone in your elbow. The doctor may also want to see whether the nerve itself slides out of its proper position when your elbow bends.
  • Movement and strength tests: You may be asked to put your arms in different positions and turn your neck from side to side to see whether that causes any pain or numbness. Your doctor may check the strength in your fingers and hand, and test for feeling in those areas.
  • X-ray: You might have an X-ray taken so your doctor can look for bone spurs or arthritis. These may be placing pressure on your nerve.
  • Nerve conduction study: In this test, the doctor stimulates your ulnar nerve in various places. An area that takes longer to respond may be where the nerve is compressed. This test is also helpful in diagnosing muscle wasting caused by nerve problems.
  • Electromyography (EMG): This test checks how the ulnar nerve and muscles around it respond to electric stimulation. The response can tell you if you have nerve damage.
  • Magnetic imaging resonance (MRI) scan: This uses a powerful magnet and radio waves to make detailed images of the inside of your elbow.
  • MR neurography: This is used to create detailed images of nerves in your body to see if there’s any damage.
  • Ultrasound: This uses sound waves to make images on a computer monitor to give your doctor a closer look at your elbow.

Once you’ve been diagnosed with ulnar nerve entrapment, it will be time to decide how to treat the problem. How bad the condition is will help you and your doctor decide whether surgery or a less invasive strategy is better.

Nonsurgical treatments include:

  • Nonsteroidal anti-inflammatory drugs:NSAIDs can lower pain and inflammation.
  • A splint or brace: These can keep your elbow straight, especially while you’re sleeping.
  • An elbow pad: This helps with pressure on the joint.
  • Occupational and physical therapy: This will help your arm and hand become stronger and more flexible.
  • Nerve-gliding exercise: Do this to help guide the nerve through the proper “tunnels” in the wrist and elbow.

If nonsurgical options haven’t eased your symptoms or there is obvious muscle damage, your doctor may suggest surgery.

The goal of surgery is to remove pressure from the nerve. In some cases, the nerve is moved as part of the operation.

Surgical treatments include:

  • Ulnar nerve anterior transposition: This moves the ulnar nerve so that it doesn’t stretch over the bony parts of the elbow joint.
  • Medial epicondylectomy: This removes the bump on the inside of the elbow joint, which takes pressure off the ulnar nerve.
  • Cubital tunnel release: This removes part of the compressed tube through which the nerve passes in the elbow.

If you have surgery, physical therapy to regain your arm and hand strength will likely be advised.

You might need a splint for a few weeks to help make sure the elbow heals properly.

Ongoing care for your elbow should include steps to avoid injuring or irritating the nerve further. You should be careful to avoid trauma to your elbow.

You may also need to learn, with occupational therapy, how to hold your arm differently, stretch, or take frequent breaks when doing everyday activities such as working on your computer.