Your ulnar nerve runs along the length of your arm—starting at the shoulder, running behind the elbow, and then along your forearm and wrist on the way to the hand. It’s most vulnerable to outside pressure at the elbow, where a sharp blow can produce the painful, tingling sensation we associate with our “funny bone”. Along the way, the ulnar nerve passes through several narrow openings or “tunnels” where it can become compressed or pinched (entrapped) as a result of injury or repetitive motion, causing ulnar tunnel syndrome.
If you think this condition sounds a little bit like another better-known disorder called “carpal tunnel syndrome”, you’re right! The sensations and causes are similar, they simply relate to a different nerve. The diagnosis and treatment of a compressed ulnar nerve depends on exactly where the nerve has become pinched. If the compression occurs along the cubital tunnel near the inner edge of the elbow, the resulting disorder is called “cubital tunnel syndrome”. This is the more common location, but compression of the ulnar nerve can also occur in the ulnar tunnel (sometimes referred to as “Guyon’s canal”), near the wrist. When it does, the resulting disorder is called “ulnar tunnel syndrome” or “Guyon’s canal syndrome”.
When the ulnar nerve becomes pinched in one of these areas as a result of repetitive motion and repetitive stress, a person can develop long-term symptoms ranging from mild discomfort and muscle weakness to disabling pain. Cubital tunnel syndrome tends to manifest as pain and numbness in the elbow, tingling and weakness in the ring and little fingers, decreased overall grip strength, and markedly reduced ability to pinch the thumb and little finger. In extreme cases, it can also cause a claw-like deformation of the hand. Ulnar tunnel syndrome produces similar symptoms, along with a burning pain in the wrist and a “pins and needles” sensation in the ring and little fingers.
As with carpal tunnel syndrome, the symptoms associated with ulnar nerve entrapment start small, but because the compression is caused and aggravated by repetitive motion, continued repetitive motion can aggravate the condition and make it more serious. A common cause of ulnar tunnel syndrome, for example, is the pressure exerted on the hands, wrists, and forearms by avid bicyclists gripping their handlebars. Similar pressure can be exerted even in an office setting, by repetitive actions such as pushing hard against the surface of a desk with a computer mouse. Cubital tunnel syndrome is often caused by actions that put increased, repetitive pressure on the elbow, such as sleeping with the arm folded up.
Treatment of either of these forms of ulnar nerve compression varies along with the location of the nerve entrapment and the seriousness of the condition. Conservative treatment includes identifying and then stopping the activities that cause and aggravate the condition, applying ice packs, and taking over-the-counter analgesics to treat the pain and fight inflammation. Sometimes splints are worn to protect the nerve and retrain the arm into using less stressful motions. More serious cases can be treated by physical therapy, occupational therapy, and chiropractic adjustments. Some studies have shown that chiropractic adjustment is particularly effective in the treatment of cubital tunnel syndrome.