Ulnar Nerve Entrapment

Ulnar nerve entrapment is a condition when the ulnar nerve, a nerve than runs near the elbow, becomes pinched or trapped.

The ulnar nerve passes by many narrow tunnels and outlets that may cause the nerve to become trapped. Some causes of a trapped or pinched ulnar nerve are from existing neck problems, elbow and neck abnormalities, tumors, and infections. When compression occurs at the elbow, numbness typically occurs in the small “pinky” finger, ring finger and the back of the hand near the small “pinky” finger.

Ulnar nerve entrapment is compression of one of the largest nerves of the arm. The nerve runs down the humerus to the elbow, and at this point, it passes very close to the skin. In fact, hitting your elbow in this area traumatizes the ulnar nerve and is frequently called “hitting your funny bone.” The nerve runs under the medial epicondyle, or the inside portion of your elbow, through a tunnel known as the cubital tunnel. It then continues down the inside of the arm, hugging close to the bone it is named for, the ulna. The ulna is one of two bones in the forearm, and it is located on the side of the little finger.

At the wrist, the nerve enters another tunnel, or narrowing between the bones, called Guyon’s tunnel. From there, it supplies feeling and movement to the little finger and half of the ring finger. In addition, it is responsible for a large portion of the palm and the smaller muscles of the hand that are used in fine motor control. The nerve can become entrapped anywhere along its length, but it is most commonly pinched at the cubital tunnel.

Your hands are a vital component of your everyday life, and the SoCal Pain Center professionals understand how difficult it can be to use a hand that refuses to function properly. We have a pain management doctor that can help you with your condition, and a physical therapist that can assist you with splints and exercises to relieve your pain.


Ulnar nerve entrapment occurs most frequently at the cubital tunnel. For entrapment at the Guyon’s tunnel, the cause may be from swelling in the ligaments, trauma to the wrist, or arthritis. The causes of ulnar nerve entrapment at the elbow are more complex. The nerve may slide out from behind the medial epicondyle and then back into the groove of the tunnel. This constant shifting can cause irritation to the nerve and lead to symptoms.

Postures which put a great deal of pressure on the elbow, such as pressing your elbows on an armrest while typing, can lead to irritation of the nerve and swelling of the surrounding tissue. Edema in the hands and arms can cause the tunnel to shrink and lead to symptoms. Any posture when your elbow is bent for long periods of time, such as when sleeping, can lead to pain and numbness along the ulnar nerve track. Finally, trauma to the inside portion of the elbow can permanently damage the nerve and require medical attention.


Although the injury or entrapment occurs in your elbow, you will feel the symptoms in your hand. Symptoms of ulnar nerve entrapment include:

• Your little finger and ring finger “falling asleep”

• Difficulty moving your last two fingers

• Numbness and tingling in the last two fingers

• Your grip will weaken

• You will lose coordination in your fingers

• In severe cases, your muscles can waste

Muscle wasting, once it occurs, is not reversible. The other symptoms of ulnar nerve entrapment are reversible provided that action is taken to prevent the entrapment and the entrapment has not permanently damaged the nerve. In some cases, the nerve is pinched for so long that it cannot regenerate itself. In this case, chronic pain, numbness, weakness, and paralysis of the little finger and part of the ring finger are common.


You can take a few steps on your own to treat ulnar nerve compression. For instance, you can ensure that you do not rest your elbows on an armrest when typing, take frequent breaks to extend your elbows, and avoid any activities that lean your elbow against a pressure source. If you have symptoms in your sleep, you can wrap your arm in a towel or wear an elbow pad backwards to keep your arm extended.

If these measures do not work, you can take anti-inflammatory drugs, such as ibuprofen or prednisone, to decrease the amount of swelling in the cubital tunnel. Bracing, splinting, and special exercises known as nerve glide exercises can help the nerve stay within the cubital tunnel.

Severe cases that have led to muscle wasting or are not responding to conservative treatment may need surgery. The ligaments inside the cubital tunnel can be severed to provide more room for the ulnar nerve. A more common procedure involves making an incision along the inside of the elbow and moving the ulnar nerve from behind the medial epicondyle to the front. Finally, the epicondyle can be cut back to allow the nerve to move freely.

At SoCal Pain Center, we are experts in nerve pain and peripheral neuropathy, and we can help you deal with the pain and numbness that occur with ulnar nerve entrapment. Our pain management doctor can help you with medications and our staff can assist you with bracing and physical therapy on your arm. Contact us today for a consultation.


American Academy of Orthopedics; Ulnar Nerve Entrapment at the Elbow (Cubital Tunnel Syndrome); August 2011


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