Cubital Tunnel Syndrome

Cubital tunnel syndrome is a condition that happens when your ulnar nerve gets rubbed or pressed. The ulnar nerve is one of the three main nerves in your arm. It runs from your neck through a narrow space at your elbow joint called the cubital tunnel and down into your hand. 

Cubital tunnel syndrome is sometimes called ulnar nerve entrapment. When you hit the funny bone in your elbow, you are actually hitting your ulnar nerve. That’s why you get that shock-like feeling. 

The cubital tunnel space is tight, so it’s easy for the ulnar nerve to get squeezed, restricted or compressed.

With cubital tunnel syndrome, you might notice an aching pain on the inside of your elbow. But most symptoms appear in your hand, especially when your elbow is bent:

• Numbness or tingling in your ring finger and little finger: These sensations can come and go. They may be worse when your elbow is bent, like when you are driving or holding a phone. You might even wake up at night and notice that your fingers feel numb.
• A "falling asleep" sensation: You might feel your ring finger and little finger fall asleep. This sensation can make it harder to move your fingers.
• Weakness and clumsiness: In more severe cases, your grip might get weaker and your fingers might lose coordination. It could be harder for you to type or play an instrument. 

What causes cubital tunnel syndrome?

It’s not always clear what causes cubital tunnel syndrome. These risk factors can make it more likely:

• Bending your elbow repeatedly or keeping it bent for a long time: A bent elbow can irritate the nerve and keep it from getting enough blood. If you sleep with your elbows bent, it can make the condition worse.
• Leaning on your elbow: Using an armrest on a desk chair or driving with your arm resting on an open window can put pressure on the nerve.
• Nerve instability: The ulnar nerve may slide out from behind the medial epicondyle (the bony bump on the inside of your elbow) when you bend your elbow. Over time, this sliding can irritate the nerve.
• Fluid buildup: Swelling or fluid in your elbow can compress the nerve.
• Trauma: A blow to the inside of your elbow, often called "hitting your funny bone," can cause pain, electric shock sensations and numbness.
• Injuries: Having fractured or dislocated your elbow in the past increases your risk. 
• Medical conditions: Your risk is higher if you have bone spurs or arthritis in the elbow joint, cysts near the elbow joint, rheumatoid arthritis or diabetes.
• Certain activities: Jobs or hobbies with a lot of elbow bending, such as baseball pitching or long hours of driving or typing, are risk factors.

Your health care provider will review your medical history and ask you about your symptoms, work, activities and medications. 

They will check your elbow and hand to see which nerve is compressed. They might also examine your neck, since a pinched nerve in the neck may cause similar symptoms.

Your provider may perform these tests:

• Tinel's sign: Tapping over the ulnar nerve at the funny bone to show whether it causes a shock-like sensation in your little finger and ring finger. That sensation can mean your nerve is irritated.
• Nerve movement check: Seeing if your ulnar nerve slides out of position when you bend your elbow.
• Range of motion and sensation tests: Moving your neck, shoulder, elbow and wrist to see if different positions cause symptoms. 
• Strength tests: Seeing how well you can spread your fingers apart and bring them back together and testing your grip strength.

These tests may then be used to confirm the diagnosis:

• Nerve conduction study (NCS): This test measures how fast electrical signals travel down a nerve. The electricity slows where a nerve is compressed. It may show whether the pinched nerve is at the elbow, wrist or neck.
• Electromyogram (EMG): This test checks to see if the forearm muscles are working as they should. If not, the ulnar nerve may be compressed.  
• Ultrasound or MRI: Imaging tests can show the cubital tunnel and the area around it. 
• X-rays: Most causes of ulnar nerve compression won’t show up on X-rays, but they can show bone spurs or arthritis that could be compressing the nerve.

Cubital tunnel syndrome can feel like other nerve or joint problems, such as carpal tunnel syndrome or medial epicondylitis (golfer’s elbow). It’s important to get an accurate diagnosis so you receive the right treatment. If the nerve is compressed for a long time, it can lead to permanent damage and lost function in your hand.

Treatment depends on how severe your symptoms are. These simple changes and at-home care usually help:

• Modifying your activities: Try not to keep your arm bent for a long time or putting pressure on the inside of your arm. If you use a computer often, raise your chair to avoid resting your elbow on the armrest. If you need to use the armrest, use padding or a cushion.
• Bracing or splinting: A padded brace or splint you wear at night can keep your elbow straight. You can also try loosely wrapping a towel around your straight elbow or wearing an elbow pad backward while sleeping.
• Anti-inflammatory medicines (NSAIDs): An anti-inflammatory medicine, such as ibuprofen or naproxen, may help reduce swelling and pain if your symptoms just started. 
• Nerve gliding exercises: Your provider may suggest exercises to help the nerve slide more freely. They may also help prevent stiffness.

If these treatments don’t help, the nerve is very compressed or you have muscle weakness or damage, your provider may recommend surgery. Most people go home the day of surgery. Options include:

• Cubital tunnel release: Surgeons divide the ligament on the top of the cubital tunnel to make it bigger, so there’s less pressure on the nerve. 
• Ulnar nerve transposition: Surgeons move the nerve to a new position, which keeps it from getting caught and stretching when your elbow is bent. 
• Medial epicondylectomy: Surgeons remove part of the bone to create more room for the nerve and release the pressure. 

You can’t always prevent cubital tunnel syndrome, but these tips can help reduce your risk:

• Avoid leaning: Do not rest your elbows on hard surfaces for a long time. Don’t put pressure on the inside of your arm.
• Use proper posture: If you use a computer often, make sure your chair is not too low and try not to rest your elbow on the armrest.
• Take breaks: Give your arms and elbows a break when you’re using them repeatedly or for a long time.
• Keep your elbows straight at night: Try wrapping a towel around your straight elbow or wearing an elbow pad backward.
• Keep your arms flexible and strong: Take part in activities and exercises that build flexibility and strength.

You need a healthy ulnar nerve so you can use your arm and hand properly and feel things with your pinky and ring finger. If you have signs of cubital tunnel syndrome, don’t wait. The earlier you get care, the better your chances of full recovery.

Contact a health care provider if:

• You have severe symptoms
• Symptoms last more than six weeks
• Pain or trouble moving affects your regular daily activities
• Pain does not improve or gets worse with home treatment