Getting a Grip on Hand Problems: Carpal Tunnel, Arthritis

by Food and Drug Administration (FDA)

A trip to the supermarket or signing a paycheck didn't used to rank high on the list of 31-year-old Wanda Wood's concerns. But now, everyday chores like pumping gas and carrying groceries to the car are ordeals for her.

Wood can't hold a pen long enough to finish signing her check. She has trouble grasping a nozzle to fill her gasoline tank. And she can't grip her groceries to keep them from falling out of her hands.

"It's when a jar of tomato sauce cracks all over the pavement that I get real embarrassed," said Wood, a Richmond, Va., former postal worker. "It's pretty tough to handle when you're standing in a parking lot covered with red goo."

Like Wood, an increasing number of American workers are experiencing the sudden onset of one of several cumulative trauma disorders affecting the hands, according to James McGlothlin, Ph.D., a research hygienist at the National Institute for Occupational Safety and Health in Cincinnati. Doctors often call them repetitive strain injuries (RSIs).

RSI is a catch-all term used to refer to many painful conditions, such as trigger finger, nerve spasms, and carpal tunnel syndrome. They can cause stiffness, swelling, tingling, weakness, numbness, and, in some cases, irreversible nerve damage.

Carpal tunnel syndrome is the most frequently reported RSI, with 192 cases per 100,000 workers in 1989, according to the U.S. Public Health Service. It occurs when tissues on the palm side of the hand swell, compressing or entrapping the important median nerve, which runs through this area. Numbness and tingling usually start in the wrist, and can radiate down to the thumb and fingers, or up to the elbow. Many patients feel pins and needles when their wrist is tapped. Weakness occurs on effort. For example, patients may suddenly drop objects they are holding. A nerve conduction test, a recording of the electrical activity of the hand and arm muscles, is helpful in diagnosing this disorder.

Other RSIs include nerve spasm and "trigger finger." When nerve entrapment and the pressure caused by it occurs over a long period, the nerve can become irritated and go into spasms, stimulating muscle activity that eventually causes pain similar to severe muscle cramps.

When finger tendons, fibrous bands of tissue that connect muscle to bone, get irritated, they can grow nodules, which, at the points of attachment, get caught in the lubricating sheath that surrounds them. When this happens, the finger can become stuck; this condition is called trigger finger.

RSIs are self-limiting conditions that result from excessive use of the muscles and tendons of the hands, wrists and forearms. Meat cutters, auto workers, cashiers, journalists, keyboard operators, and others who spend long hours at repetitive chores are particularly vulnerable.

Wood used to spend long shifts operating a letter sorter, typing hours at a time at a computer keyboard to route the mail to its destination.

"My pain eventually became so severe that it worked its way from my fingers to my wrist to my elbow until it felt like a constant crook in my neck," she said.

Hopes for Help

Because the consequences of these disorders are so high, the goal of safety and health professionals across the country is to collect information on which to base decisions about the best ways to prevent and treat these illnesses.

But this is not an easy task. For example, some proposed treatments have not been substantiated by controlled clinical trials.

According to John Vanderveen, Ph.D., director of the Food and Drug Administration's division of nutrition, "We have from time to time dealt with claims for the use of nutrients to prevent or treat carpal tunnel syndrome, but could only find anecdotal reports."

He said, "It's difficult to do such studies because animal models are more tenuous to tease out pain and performance data from than humans. So right now we don't know if basic clinical research is likely to support such claims."

In addition to RSIs, various forms of arthritis can cause hand problems. Rheumatoid arthritis, for example, is a chronic, autoimmune disease affecting the entire musculoskeletal system. Osteoarthritis, a degenerative, "wear and tear" condition can also affect the hands.

Vanderveen said researchers are investigating the innovative use of omega-3 fatty acids, found in fish oils, to help suppress the disease by curtailing production of prostaglandins, a series of hormone-like substances associated with inflammation that occurs in arthritis. Vanderveen cautions that it's still premature at this time to think that these fatty acids will be therapeutic for many arthritis patients.

Today the best bet for RSI patients is to cope with the condition in ways similar to patients with arthritis. Such coping skills include protecting and caring for their joints and using OTC drugs such as aspirin or ibuprofen (Advil, Nuprin, Motrin IB) for mild to moderate symptoms or prescription NSAIDs (nonsteroidal anti-inflammatory drugs) for stronger anti-inflammatory relief.

About the Author

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