Using Computer Doesn't Increase Risk Of Carpal Tunnel Syndrome, Study Finds

Using a computer at work doesn't increase your chances of developing carpal tunnel syndrome, according to a study published in the June 12 issue of Neurology, the scientific journal of the American Academy of Neurology.

"We wanted to do this study because conventional wisdom says that using a computer increases your risk of developing carpal tunnel, but few studies have been done to see how often carpal tunnel actually occurs in computer users," said study author and neurologist J. Clarke Stevens, MD, of the Mayo Clinic in Rochester, Minn.
Stevens said most of the studies showing that repetitive motion causes carpal tunnel involve workers in meatpacking plants or other industrial jobs, not computer users.

This study examined 257 employees at the Mayo Clinic in Scottsdale, Ariz., who used a computer frequently in their jobs. "Many of the computer users in the study had experienced feelings of numbness or 'pins and needles' in their hands, but the percentage who actually met the medical criteria for carpal tunnel syndrome was similar to other estimates of how often carpal tunnel occurs in the general public," Stevens said.

For the study, researchers sent a questionnaire to employees who used computers for much of their jobs, such as secretaries and transcriptionists. They reported using the computer for an average of six hours per day. Of the 257 people studied, 30 percent said they had experienced pins and needles sensations or numbness in their hands.
Those people then completed a questionnaire on carpal tunnel symptoms and a diagram to show where their symptoms occurred to determine whether they met the clinical criteria for carpal tunnel syndrome. Twenty-seven people met the criteria, or 10.5 percent of the original study group.
Stevens said those who had symptoms of numbness or tingling but did not have carpal tunnel had mild symptoms that occurred briefly. Some may have had problems with another nerve in the arm, the ulnar nerve. Carpal tunnel affects the median nerve.
The researchers then tested the nerves of those who met the criteria to see if electrodiagnostic laboratory tests would confirm the diagnosis.

The nerve conduction studies confirmed the diagnosis in nine people, or 3.5 percent of the 257 study participants.
"These percentages are similar to percentages found in other studies looking at how often carpal tunnel occurs in the general population -- not just computer users," Stevens said.
The researchers also found no significant differences between the computer users who had carpal tunnel and those who did not.

"They had similar occupations, number of years using the computer and number of hours using the computer during the day," Stevens said. "So there were no differences that might point to computer use as a factor in causing carpal tunnel." Stevens said the results shouldn't be interpreted to mean that the repetitive motions involved in using a computer can never lead to problems for people.

"There are a lot of aches and pains associated with using a computer," he said. "We just found that, at least in this group, frequent computer use doesn't seem to cause carpal tunnel syndrome." Additional studies with large groups of people should be done to see if these results can be confirmed, Stevens said.