What is Cubital Tunnel Syndrome?
Cubital tunnel syndrome is caused by compression of the ulnar nerve when it passes under a bony bump (medial epicondyle) on the inside portion of the elbow. In this area, the nerve is relatively unprotected and can be trapped between the bone and the skin in a tunnel called the cubital tunnel. Though it is not an actual bone, this area is commonly called your “funny bone.” When you hit the “funny bone” just the right way, you have actually hit the ulnar nerve. This contact sends a sensation of tingling, numbness and pain along the inside of your arm and down to the ring and little fingers. When the ulnar nerve is compressed, it causes the same type of symptoms. The ulnar nerve can be pinched at any point along its length, but the most common site of compression is on the cubital tunnel.
Cubital tunnel syndrome often results from prolonged stretch or pressure on the nerve. When the arm is bent for a long time, such as when holding the phone, it stretches the ulnar nerve across the inside of the elbow, creating a traction force that decreases the blood flow to the nerve and may cause nerve irritation. Prolonged pressure on the nerve may happen, for example, when the inside part of the elbow leans against a table and the ulnar nerve is pushed over the bone, which may cause the sensation of tingling, numbness and pain along the inside of your arm and hand.
Signs and Symptoms
Cubital tunnel syndrome can occur after a traumatic incident such as an elbow fracture, or it can develop slowly over time. It usually begins with numbness and/or tingling sensations (pins and needles) on the inside of the forearm extending down into the hand. Typical symptoms include:
Intermittent pain or numbness and tingling brought on by sustained bending of the elbow over a long period of time
Tenderness on the inside of the elbow where the nerve is close to the surface
Decreased sensation or difficulty telling the difference between sharp and dull objects touching the inside of the forearm
Later symptoms sometimes include:
Difficulty gripping and holding on to objects (clumsy hands)
Muscle wasting of the small muscles of the hand
A hand deformity in which the fingers bend inward, referred to as an “ulnar claw hand”
How Is It Diagnosed?
Cubital tunnel syndrome can be diagnosed by a physical therapist or a physician. Your physical therapist will typically perform a comprehensive evaluation that may include assessment of your neck to rule out compression of the nerve where it starts in the neck. After determining that the nerve being compressed is truly the ulnar nerve, your physical therapist will use tests that may include:
Observation and inspection of the elbow and forearm
Touching and moving the arm in the area of the nerve to determine its relationship to the elbow and its stability in the groove behind the elbow where the nerve travels
Tapping the nerve at the elbow (the Tinel’s sign test)
A sensory examination that includes both light touch and a test of the ability to distinguish between sharp or dull stimulus and temperature
Checking the strength of specific muscles of your hand
Checking your pinching and gripping ability
Cubital tunnel syndrome can be accurately diagnosed clinically without additional testing. Occasionally you may be referred for electrodiagnostic tests called electromyography (EMG) and/or nerve conduction study (NCS). These tests evaluate the ability of the nerve to conduct signals along its full length. They can help determine the exact site of the compression and estimate the extent of the compression.
How Can a Physical Therapist Help?
Many cases of cubital tunnel syndrome can be treated without surgery. Your physical therapist will determine the activities that bring on your symptoms. The recommendations at this point will be to avoid those activities for a time. Remember, the nerve is irritated and at times swollen. If the irritation and swelling can be reduced, the symptoms should resolve.
In more advanced cases, your physical therapist will modify your activity and may recommend you use a splint to take the pressure off of the nerve. As your condition begins to improve, your therapist may teach you:
Range-of-motion exercises to help return full length to the muscles that have shortened due to protective posturing, and to maintain the normal length of those that have remained unaffected.
Muscle strengthening exercises to help restore the strength that has been lost over time. Your therapist will help pick the exercises that are right for you.
“Nerve gliding” exercises. Nerves actually have the ability to “stretch out.” Your therapist is educated in the proper positions for appropriate nerve stretches, and will work with you to ensure that safe and gentle stretching is achieved. In cubital tunnel syndrome, the nerve can become shortened; these exercises are an effective means of returning the nerve to its normal length.
Sometimes surgery is required. The longer you have experienced symptoms and the more you experience weakness, numbness, tingling, and pain the more likely you are to need surgery. The goal of surgery is to relieve the pressure on the nerve.
Your physical therapist will design an individual program of post-surgical therapy based on the operation and the surgeon’s instructions. Each surgery will require a unique treatment regimen, but the post-surgical rehabilitation will involve many of the pre-surgical elements discussed above, with the exclusion of nerve gliding exercises. Activity modification will be a big part of your post-surgical rehabilitation to prevent recurrence of your symptoms.
Can this Injury or Condition be Prevented?
Little is known about prevention of cubital tunnel syndrome. Often, the syndrome is not diagnosed until symptoms are already present. However, some general precautions may be taken.
Obesity has been linked by some researchers to cubital tunnel syndrome. Healthy lifestyle choices and a reduction in your weight may help prevent its development.
People in occupations that require holding the elbow in a bent position should be encouraged to perform consistent positional changes to take stress off of the ulnar nerve.
Diabetes has been recognized as a risk factor.
Recommendations for activity modification can sometimes be disruptive to employment, but they have been shown to have the most significant positive response when treating cubital tunnel syndrome non-surgically.
Real Life Experiences
Cara is a nursing-home administrator who recently has begun to feel intermittent pain in her elbow and numbness and tingling down on the inside of her hand and forearm. Initially, she noticed her pain while talking on the phone. Cara’s pain would come and go but she could change her position, moving from a bent position to a straight one, and this would reduce her pain. Over the past month, however, she has felt constant pain in her elbow and has had difficulty gripping her tennis racquet; she feels her tennis game has suffered as a result. Cara’s tennis pro suggests she see a physical therapist.
After a thorough evaluation, Cara’s therapist tells her she is suffering from cubital tunnel syndrome and recommends conservative treatment. They begin with light stretching exercises, which include nerve gliding to maintain the flexibility and motion of the nerve when the arm is bent. Cara is given a splint that keeps her elbow slightly bent. This position takes the pressure off the nerve.
After 4 weeks of treatment and splint use during the day, Cara’s splint is discharged and she slowly resumes normal activity. She has limited the time she spends on the phone because this position increased her symptoms in the past. After 8 weeks, she is back to playing tennis and has no problem gripping her racquet.
This is a typical case with mild to moderate symptoms. More severe symptoms, especially those with muscle wasting and hand deformities, should be evaluated by a physician.