RSI Reexamined

Spending long stretches of time at the computer doesn’t increase the risk of developing carpal tunnel syndrome, a painful wrist condition, a study said.

Mayo Clinic scientists detected carpal tunnel syndrome in about 10% of 257 study participants, all of whom worked a maximum of seven hours a day at a computer. That is about the same injury rate seen in previous studies of workers who spent little time at the computer, the researchers said.

Employees with possible symptoms, such as numbness and tingling of the hands, were evaluated and tested for carpal tunnel syndrome. The research team said only 27 people met the diagnostic criteria for the repetitive stress injury, in which the median nerve in the wrist swells within a narrow tunnel of ligaments and bone, causing pain and nerve damage.

“The findings are contrary to popular thought, but nobody has studied the problem carefully,” said J. Clarke Stevens, a neurologist at the Mayo Clinic and lead author of the study. “There has been very little formal study of carpal tunnel syndrome. . . . Few [published] studies looked at this in a scientific way.”

Stevens’ group surveyed 314 employees in the Mayo Clinic’s Scottsdale, Ariz., office who were identified as heavy computer users; 257 responded. Most of them were secretaries working with billing documents, Stevens said.

The team’s ability to draw conclusions from the study may have been limited by the small study size and the fact that there was no comparison group. That meant that the team had to rely on older, potentially flawed studies to gauge the “normal” rate of carpal tunnel syndrome in the general population.

“It doesn’t have a modern control group. . . . Without a current control, it’s hard to draw conclusions,” said David Rempel, a carpal tunnel syndrome researcher at UC San Francisco. “There are other studies that have the opposite conclusion; this kind of small study can’t answer the question.”