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Cubital tunnel release tends to work best when the nerve compression is mild or moderate and the nerve does not slide out from behind the bony ridge of the medial epicondyle when the elbow is bent.

Ulnar Nerve Entrapment

Ulnar nerve entrapment affects your ulnar nerve in your arm. Cubital tunnel syndrome occurs in your elbow, while Guyon’s canal syndrome affects your wrist. Overuse injuries, cysts and other problems can stretch or put pressure on the ulnar nerve. You may have hand and finger weakness, numbness, pain or tingling. At-home treatments can help.

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Overview

What is ulnar nerve entrapment?

Ulnar nerve entrapment is the most common ulnar nerve problem. Ulnar nerve entrapment occurs when something puts pressure on your ulnar nerve in your elbow or wrist. Nerve entrapment is a type of nerve compression syndrome.

Compression (a pinched nerve) may lead to inflammation causing nerve (neuropathic) pain and neuropathy (nerve damage). In some cases, this may affect your grip strength, making it difficult for you to grasp items.

What is the ulnar nerve?

Your ulnar nerve is a single nerve in a network known as the peripheral nervous system, which carries information to and from your brain by route of your spinal cord.

Your ulnar nerve helps you bend and straighten your pinky and ring fingers so you can grasp items. The nerve also sends sensory information about touch, pain and temperature. If you bump your ulnar nerve in your elbow, you may experience a tingling “funny bone” sensation. Each arm has an ulnar nerve.

What are the types of ulnar nerve entrapment?

Ulnar nerve entrapment can occur at your elbow or wrist. Types include:

• Cubital tunnel syndrome: Pressure or pulling and stretching of your ulnar nerve in your elbow region.
• Guyon’s canal syndrome: Pressure on your ulnar nerve in your wrist region.

How common is ulnar nerve entrapment?

Cubital tunnel syndrome is the second-most common peripheral neuropathy that affects your upper limbs. (Carpal tunnel syndrome, a pinched median nerve in your wrist, is the most common.) Guyon’s canal syndrome is rare.

Symptoms and Causes

What causes ulnar nerve entrapment?

Activities that stretch your ulnar nerve at your elbow, or put a lot of pressure on your elbow, can lead to cubital tunnel syndrome. Sleeping with your elbows bent for long periods can cause or worsen symptoms of ulnar nerve entrapment.

Ganglion cysts are noncancerous fluid-filled sacs that form near your wrist joint. These cysts cause up to 40% of Guyon’s canal syndrome. Another 45% of Guyon’s canal syndrome diagnoses occur for no apparent reason (idiopathic). Less commonly, cysts can also cause pressure on the ulnar nerve within your elbow.

Other causes of ulnar nerve entrapment and damage include:

• Accidents and trauma.
• Arthritis.
• Broken bones and bone spurs.
• Complications from surgeries to treat carpal tunnel or shoulder fractures.
• Diabetes.
• Dislocated elbow.
• Pressure from casts or splints or using crutches.
• Tumors or cysts.

What are the risk factors for ulnar nerve entrapment?

Ulnar nerve entrapment affects more men than women. People who do jobs or activities that require a lot of elbow or wrist pressure or stretching are most at risk, such as:

• Baseball players, golfers and tennis players.
• Bicyclists.
• Construction workers.
• People who smoke.
• Typists, writers and others who use a keyboard frequently.
• Weightlifters.

What are the symptoms of ulnar nerve entrapment and damage?

Signs come on gradually and may come and go. Symptoms may get worse at night or when you do activities that stretch or put pressure on your elbow or wrist.

Symptoms of ulnar nerve entrapment and damage include:

• Curving pinky and ring fingers (like a claw).
• Elbow pain (cubital tunnel syndrome) or wrist pain (Guyon’s canal syndrome).
• Numbness and tingling in your pinky and ring fingers.
• Hand weakness that makes it hard to hold onto or pick up items or perform tasks like writing or buttoning a shirt.
• Muscle loss in your ring or pinky fingers (a rare symptom).

Diagnosis and Tests

What physical exams can diagnose ulnar nerve entrapment?

Your healthcare provider may perform several tests during your physical exam to evaluate your symptoms. These tests seem simple, but they help your healthcare provider assess finger and hand strength. They include:

• Froment’s test: Your health provider observes how you hold a piece of paper between your thumb and index finger. Flexing at the interphalangeal joint at the tip of the thumb may indicate a nerve problem.
• Tinel’s test: Your healthcare provider gently taps your elbow’s funny bone (ulnar nerve). An extreme shock-like sensation in your pinky or ring finger may suggest a nerve problem.
• Wartenberg’s sign: Your healthcare provider watches as you spread your fingers apart and then bring them back together while resting your hand on a flat surface. You may have a nerve problem if you can’t bring your pinky finger in to meet with the others.

What diagnostic tests can detect ulnar nerve entrapment?

These tests can confirm or rule out ulnar nerve entrapment:

• Electromyography(EMG), including nerve conduction studies, measure how well signals travel through nerves to stimulate muscles.
• MRI,neuromuscular ultrasoundor X-rays can show signs of nerve compression and help rule out problems like arthritis, ligament injuries and fractures.

Management and Treatment

What are nonsurgical treatments for ulnar nerve entrapment?

Nonsurgical treatments for ulnar nerve entrapment include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve nerve (neuropathic) pain and swelling.
• Physical and occupational therapy to help you improve flexibility and learn to perform tasks in new ways that are less likely to irritate your ulnar nerve. You may learn nerve-gliding exercises to help your ulnar nerve move more smoothly through ulnar tunnels.
• Splints or braces to support your wrist or elbow.

What are surgical treatments for ulnar nerve entrapment?

If nonsurgical treatments don’t help, you may need surgery. Depending on the cause of the nerve entrapment, surgery can:

• “Release” your pinched ulnar nerve at the point of entrapment.
• Remove tumors or cysts.
• Move your ulnar nerve to the front of your bony elbow joint.

Prevention

How can I prevent ulnar nerve entrapment?

These steps can lower your risk of developing ulnar nerve entrapment, or ease symptoms:

• Extend and stretch your arms throughout the day if you’re involved in activities that keep your elbows bent for an extended time.
• Don’t rest your elbows on an office chair or desk while typing or working on a computer.
• Secure a towel around your straightened arm at night to keep from sleeping on a bent elbow. Or you can wear an elbow brace backward on the elbow joint.

Outlook / Prognosis

What are the complications of ulnar nerve entrapment?

Ulnar nerve entrapment in your elbow or wrist that’s severe can cause muscle loss in your hand. This damage may be permanent in some cases, which is why it’s important to see your healthcare provider early about symptoms.

What’s the prognosis for people with ulnar nerve entrapments?

About half of all people with ulnar nerve entrapment get symptom relief through nonsurgical means.

When needed, surgery may eliminate nerve pain and other symptoms. But for about 1 in 8 people with cubital tunnel syndrome, symptoms may return if the procedure doesn’t fully treat the underlying cause. There’s also a risk of surgical damage to your median nerve, ulnar artery or ligaments in your elbow or wrist.

Living With

When should I call my doctor?

You should call your healthcare provider if you experience:

• Difficulty picking up or holding onto items.
• Elbow or wrist pain.
• Hand or finger numbness or tingling.
• Problems doing daily tasks like buttoning a shirt or holding a pen.

A note from Cleveland Clinic

Ulnar nerve entrapment occurs when something irritates or puts pressure on your ulnar nerve that runs down your arm. Cubital tunnel syndrome affects your ulnar nerve in your elbow. It’s the most common type of ulnar nerve entrapment. Guyon’s canal syndrome, which affects the nerve in your wrist, is a rare peripheral neuropathy. Talk to your healthcare provider if you experience numbness, pain or tingling in your hands or fingers. You can take steps to prevent nerve damage.

Last reviewed by a Cleveland Clinic medical professional on 01/05/2022.

References

• Aleksenko D, Varacallo M. Guyon Canal Syndrome. (https://www.ncbi.nlm.nih.gov/books/NBK431063/) [Updated 2020 Jul 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Accessed 1/5/2022.
• American Academy of Orthopaedic Surgeons. Ulnar Nerve Entrapment at the Elbow (Cubital Tunnel Syndrome). (https://orthoinfo.aaos.org/en/diseases–conditions/ulnar-nerve-entrapment-at-the-elbow-cubital-tunnel-syndrome/) Accessed 1/5/2022.
• American Society for Surgery of the Hand. Cubital Tunnel Syndrome. (https://www.assh.org/handcare/condition/cubital-tunnel-syndrome) Accessed 1/5/2022.
• Chauhan M, Anand P, M Das J. Cubital Tunnel Syndrome. (https://www.ncbi.nlm.nih.gov/books/NBK538259/) [Updated 2021 Apr 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Accessed 1/5/2022.
• Davis DD, Kane SM. Ulnar Nerve Entrapment. (https://www.ncbi.nlm.nih.gov/books/NBK555929/) [Updated 2020 Dec 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Accessed 1/5/2022.
• Merck Manual (Consumer Version). Cubital Tunnel Syndrome. (https://www.merckmanuals.com/home/bone,-joint,-and-muscle-disorders/hand-disorders/cubital-tunnel-syndrome) Accessed 1/5/2022.
• Radiopaedia. Cubital Tunnel Syndrome. (https://radiopaedia.org/articles/cubital-tunnel-syndrome) Accessed 1/5/2022.
• Radiopaedia. Guyon’s Canal Syndrome. (https://radiopaedia.org/articles/guyons-canal-syndrome) Accessed 1/5/2022.

Our knowledge of orthopaedics. Your best health.

Ulnar nerve entrapment occurs when the ulnar nerve in the arm becomes compressed or irritated.

The ulnar nerve is one of the three main nerves in your arm. It travels from your neck down into your hand and can be constricted in several places along the way, such as beneath the collarbone or at the wrist. The most common place for compression of the nerve is behind the inside part of the elbow. Ulnar nerve compression at the elbow is called cubital tunnel syndrome.

Numbness and tingling in the hand and fingers are common symptoms of cubital tunnel syndrome. In most cases, symptoms can be managed with nonsurgical treatments like changes in activities and bracing. If nonsurgical methods do not improve your symptoms, or if the nerve compression is causing muscle weakness or damage in your hand, your doctor may recommend surgery.

This illustration of the bones in the shoulder, arm, and hand shows the path of the ulnar nerve.

Reproduced from Mundanthanam GJ, Anderson RB, Day C: Ulnar nerve palsy. Orthopaedic Knowledge Online 2009. Accessed August 2011.

Anatomy

At the elbow, the ulnar nerve travels through a tunnel of tissue (the cubital tunnel) that runs under a bump of bone at the inside of your elbow. This bony bump is called the medial epicondyle. The spot where the nerve runs under the medial epicondyle is commonly referred to as the “funny bone.” At the funny bone, the nerve is close to your skin, and bumping it causes a shock-like feeling.

The ulnar nerve runs behind the medial epicondyle on the inside of the elbow.

Beyond the elbow, the ulnar nerve travels under muscles on the inside of your forearm and into your hand on the side of the palm with the little finger. As the nerve enters the hand, it travels through another tunnel (Guyon’s canal).

The ulnar nerve gives feeling to the little finger and half of the ring finger. It also controls most of the little muscles in the hand that help with fine movements, and some of the bigger muscles in the forearm that help you make a strong grip.

The ulnar nerve gives sensation (feeling) to the little finger and to half of the ring finger on both the palm and back side of the hand.

Diseases & Conditions

Carpal Tunnel Syndrome

Treatment

Diseases & Conditions

Cause

In many cases of cubital tunnel syndrome, the exact cause is not known. The ulnar nerve is especially vulnerable to compression at the elbow because it must travel through a narrow space with very little soft tissue to protect it.

Common Causes of Compression

There are several things that can cause pressure on the nerve at the elbow:

• When your bend your elbow, the ulnar nerve must stretch around the boney ridge of the medial epicondyle. Because this stretching can irritate the nerve, keeping your elbow bent for long periods or repeatedly bending your elbow can cause painful symptoms. For example, many people sleep with their elbows bent, which can aggravate symptoms of ulnar nerve compression and cause you to wake up at night with your fingers asleep.
• In some people, the nerve slides out from behind the medial epicondyle when the elbow is bent. Over time, this sliding back and forth may irritate the nerve.
• Leaning on your elbow for long periods of time can put pressure on the nerve.
• Fluid buildup in the elbow can cause swelling that may compress the nerve.
• A direct blow to the inside of the elbow can cause pain, electric shock sensation, and numbness in the little and ring fingers. This is commonly called “hitting your funny bone.”

Risk Factors

Some factors put you more at risk for developing cubital tunnel syndrome. These include:

• Prior fracture or dislocation of the elbow
• Bone spurs/arthritis of the elbow
• Swelling of the elbow joint
• Cysts near the elbow joint
• Repetitive or prolonged activities that require the elbow to be bent or flexed

Symptoms

Cubital tunnel syndrome can cause an aching pain on the inside of the elbow. Most of the symptoms, however, occur in your hand.

• Numbness and tingling in the ring finger and little finger are common symptoms of ulnar nerve entrapment. Often, these symptoms come and go. They happen more often when the elbow is bent, such as when driving or holding the phone. Some people wake up at night because their fingers are numb.
• The feeling of “falling asleep” in the ring finger and little finger, especially when your elbow is bent. In some cases, it may be harder to move your fingers in and out, or to manipulate objects.
• Weakening of the grip and difficulty with finger coordination (such as typing or playing an instrument) may occur. These symptoms are usually seen in more severe cases of nerve compression.
• If the nerve is very compressed or has been compressed for a long time, muscle wasting in the hand can occur. Once this happens, muscle wasting cannot be reversed. For this reason, it is important to see your doctor if symptoms are severe or if they are less severe but have been present for more than 6 weeks.

(Left) Photo shows the appearance of normal muscle between the thumb and index finger when the fingers are pinched. (Right) In this photo, muscle wasting has occurred due to long-term ulnar nerve entrapment.

Home Remedies

There are many things you can do at home to help relieve symptoms. If your symptoms interfere with normal activities or last more than a few weeks, be sure to schedule an appointment with your doctor.

• Avoid activities that require you to keep your arm bent for long periods of time.
• If you use a computer frequently, make sure that your chair is not too low. Do not rest your elbow on the armrest.
• Avoid leaning on your elbow or putting pressure on the inside of your arm. For example, do not drive with your arm resting on the open window.
• Keep your elbow straight at night when you are sleeping. This can be done by wrapping a towel around your straight elbow or wearing an elbow pad backwards.

Loosely wrapping a towel around your arm with tape can help you remember not to bend your elbow during the night.

Doctor Examination

Medical History and Physical Examination

Your doctor will discuss your medical history and general health. They may also ask about your work, your activities, and what medications you are taking.

After discussing your symptoms and medical history, your doctor will examine your arm and hand to determine which nerve is compressed and where it is compressed. Some of the physical examination tests your doctor may do include:

• Tap over the nerve at the funny bone. If the nerve is irritated, this can cause a shock into the little finger and ring finger (Tinel’s sign) — although this can happen when the nerve is normal as well.
• Check whether the ulnar nerve slides out of normal position when you bend your elbow.
• Move your neck, shoulder, elbow, and wrist to see if different positions cause symptoms.
• Check for feeling and strength in your hand and fingers.

To perform Tinel’s test for nerve damage, your doctor will lightly tap along the inside of the elbow joint, directly over the ulnar nerve.

Tests

X-rays. X-rays provide detailed pictures of dense structures, like bone. Most causes of compression of the ulnar nerve cannot be seen on an X-ray. However, your doctor may take X-rays of your elbow or wrist to look for bone spurs, arthritis, or other places that the bone may be compressing the nerve.

Nerve conduction studies. These tests can determine how well the nerve is working and help identify where it is being compressed.

Nerves are like electrical cables that travel through your body carrying messages between your brain and muscles. When a nerve is not working well, it takes longer for it to conduct.

During a nerve conduction test, the nerve is stimulated in one place, and the time it takes for there to be a response is measured. Several places along the nerve will be tested; the area where the response takes too long is likely to be the place where the nerve is compressed.

Nerve conduction studies can also determine whether the compression is also causing muscle damage. During the test, small needles are put into some of the muscles that the ulnar nerve controls. Muscle damage is a sign of more severe nerve compression.

Nerve conduction studies measure the signals travelling in the nerves of your arm and hand.

Treatment

Unless your nerve compression has caused a lot of muscle wasting, your doctor will most likely first recommend nonsurgical treatment.

Nonsurgical Treatment

Nonsteroidal anti-inflammatory drugs (NSAIDs). If your symptoms have just started, your doctor may recommend an anti-inflammatory medicine, such as ibuprofen or naproxen, to help reduce swelling around the nerve.

Although steroids, such as cortisone, are very effective anti-inflammatory medicines, steroid injections are generally not used to treat cubital tunnel syndrome because there is a risk of damage to the nerve.

Bracing or splinting. Your doctor may prescribe a padded brace or splint to wear at night to keep your elbow in a straight position.

Nerve gliding exercises. Some doctors think that exercises to help the ulnar nerve slide through the cubital tunnel at the elbow and the Guyon’s canal at the wrist can improve symptoms. These exercises may also help prevent stiffness in the arm and wrist.

Examples of nerve gliding exercises. With your arm in front of you and the elbow straight, curl your wrist and fingers toward your body, then extend them away from you, and then bend your elbow.

Surgical Treatment

Your doctor may recommend surgery to take pressure off of the nerve if:

• Nonsurgical methods have not improved your condition
• The ulnar nerve is very compressed
• Nerve compression has caused muscle weakness or damage

There are a few surgical procedures that will relieve pressure on the ulnar nerve at the elbow. Your orthopaedic surgeon will talk with you about the option that would be best for you.

These procedures are most often done on an outpatient basis, but some patients do best with an overnight stay at the hospital.

Cubital tunnel release. In this operation, the ligament roof of the cubital tunnel is cut and divided. This increases the size of the tunnel and decreases pressure on the nerve.

This illustration shows the path of the ulnar nerve through the cubital tunnel. Structures that may compress the nerve — such as the medial epicondyle and ulnar collateral ligament — are also shown.

Reproduced from J Bernstein, ed: Musculoskeletal Medicine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2003.

After the procedure, the ligament begins to heal, and new tissue grows across the division. The new growth heals the ligament and allows more space for the ulnar nerve to slide through.

Cubital tunnel release tends to work best when the nerve compression is mild or moderate and the nerve does not slide out from behind the bony ridge of the medial epicondyle when the elbow is bent.

In this surgical photo, a cubital tunnel release has been performed to decompress, or relieve pressure on, the ulnar nerve. The arrow shows the portion of the nerve that has become narrowed over time due to compression.

Ulnar nerve anterior transposition. In many cases, the nerve is moved from its place behind the medial epicondyle to a new place in front of it. Moving the nerve to the front of the medial epicondyle prevents it from getting caught on the bony ridge and stretching when you bend your elbow. This procedure is called an anterior transposition of the ulnar nerve.

The nerve can be moved to lie under the skin and fat but on top of the muscle (subcutaneous transposition); within the muscle (intermuscular transposition); or under the muscle (submuscular transposition).

For anterior transposition of the ulnar nerve, an incision is made along the inside of the elbow (pictured) or along the back side of the elbow.

Medial epicondylectomy. Another option to release the nerve is to remove part of the medial epicondyle. Like ulnar nerve transposition, this technique also prevents the nerve from getting caught on the boney ridge and stretching when your elbow is bent.

Surgical Recovery

Depending on the type of surgery you have, you may need to wear a splint for a few weeks after the operation. A submuscular transposition usually requires a longer time (3 to 6 weeks) in a splint.

Your surgeon may recommend physical therapy exercises to help you regain strength and motion in your arm. They will also talk with you about when it will be safe to return to all your normal activities.

Surgical Outcome

The results of surgery are generally good. Each method of surgery has a similar success rate for routine cases of nerve compression. If the nerve is very badly compressed or if there is muscle wasting, the nerve may not be able to return to normal, and some symptoms may remain even after the surgery. Nerves recover slowly, and it may take a long time to know how well the nerve will do after surgery.