New Study Suggests Computer Use May Not Lead to Carpal Tunnel Syndrome

If you're one of the millions of Americans who suffer from carpal tunnel syndrome and think your computer is responsible for those cramps in your hands, you may be wrong.

A new study in the June 12 issue of Neurology found that, contrary to popular belief, typing for even up to seven hours a day on the computer doesn't necessarily increase a person's likelihood of developing carpal tunnel.

"Few studies have been done to see how often carpal tunnel actually occurs in computer users," said study author Dr. J. Clarke Stevens, a neurologist at the Mayo Clinic in Rochester, Minn. "I'd like computer users to know that prolonged use of a computer does not lead to CTS."

Stevens said many of those who complain of carpal tunnel may be misdiagnosing themselves, and found most research showing that repetitive motion causes carpal tunnel involves factory and industrial workers such as those who work in meatpacking plants.

Release of the study comes just weeks before the U.S. Department of Labor is set to hold hearings in response to President Bush's decision to toss out Clinton administration regulations designed to prevent on-the-job repetitive stress injuries.

The Mayo study examined 257 employees at the Mayo Clinic in Scottsdale, Ariz., who used a computer an average of six hours a day at work. Only 30 percent of those studied complained of symptoms resembling those of CTS. And only 10.5 percent of the original group, or 27 people, met the medical criteria for carpal tunnel.

The condition, also known as repetitive stress injury, occurs when excess pressure is put on the median nerve in the wrist, which controls hand movement. Symptoms include numbness, tingling, wrist pain, and impairment of finger movement. Certain people seem to be predisposed to the problem, and factors like weight and pregnancy are thought to play a role.

For some, the study adds weight to the argument they've made all along: That carpal tunnel is nothing more than hype that grew as exponentially as the rate of computer use.

One researcher at the University of Toronto said he's recently noticed a significant drop in carpal tunnel complaints and diagnoses. Reports of the disorder exploded in the 1990s and caused many to switch jobs, quit or scale back on their workday hours.

"The whole thing has sort of evaporated in a cloud of smoke," Edward Shorter, history of medicine chairman at Toronto, told the National Post. "The fact is that most of these people didn't have carpal tunnel syndrome. They had hysteria."

But some doctors firmly believe that despite the Mayo Clinic findings, movements like computer keying do aggravate CTS.

"Computers irritate the tendons and irritate the carpal tunnel," said Dr. Gerard Varlotta, who works with patients who have the disorder. He said it's common for CTS to flare up among people who type excessively on the computer.

Ergonomic keyboards, padding and positioning the hands and wrists so they're level are all ways to avoid the problem, according to Varlotta.

"If you take people who are at a computer with a proper ergonomic setup, I think we can minimize the risk of carpal tunnel," he said.

But Stevens said that his research found people were mistaking other signs of discomfort in the wrist area with carpal tunnel.

Many of those studied, he said, complained of the prickly "pins and needles" feeling in their hands and wrists or other mild symptoms that began and ended quickly - and some felt pressure on a different nerve in the arm, the ulnar nerve.

The Mayo researchers also used nerve-conduction lab tests and found that only nine people, or 3.5 percent of the 257 subjects, had a confirmed diagnosis of carpal tunnel.

"There are a lot of aches and pains associated with using a computer," Stevens said. "We found that, at least in this group, frequent computer use doesn't seem to cause carpal tunnel syndrome."

He and other doctors suggest that more studies examining larger numbers of people be done to confirm the Mayo findings.

Fox News' Heather Nauert, Catherine Donaldson-Evans and The Associated Press contributed to this report.