FRIDAY, April 28, 2006 (HealthDay News) -- An "ergonomic board" that provides forearm support may relieve upper body pain and disorders that can develop from spending extended hours on a computer, a new study suggests.
The device, a board that attaches to a desk and supports the forearm, lowered the risk of developing shoulder and neck problems by nearly half and significantly reduced neck, shoulder and right arm pain associated with computer work.
"Computer-related injuries mainly occur in the neck and shoulder region. The elbow and wrist are the second most common area," explained study lead author Dr. David Rempel, professor of medicine at the University of California, San Francisco. "This study, done in people who spend 30 to 40 hours a week in front of a computer, found that a forearm support can prevent some of these injuries and decrease pain."
The findings appear in the current issue of the British journal Occupational and Environmental Medicine.
For the study, researchers evaluated the impact of two ergonomic devices on the severity and incidence of these computer-related injuries. They monitored 182 employees from two customer-service center sites for one year. The employees were randomly put into one of four groups, each receiving a different "ergonomic intervention." One group received ergonomic training; a second got the training plus a trackball mouse; a third group received the training plus forearm support; and the fourth received the training plus a trackball mouse and forearm support.
Each week the participants filled out a questionnaire, which included assessing pain in the neck, shoulders and left and right arms on a scale of 0 to 10; physicians also diagnosed any new upper body musculoskeletal disorders that developed.
The result: The forearm support boards plus ergonomic training provided the most protection against computer-related injuries. Specifically, the boards reduced the risk of neck and shoulder disorders by nearly half, compared to the group that only received ergonomic training, and resulted in an average 0.5 point drop (on the 10-point scale) in neck and shoulder pain. This may be a small drop, Rempel said, but it could be significant in a large population, said Rempel. The number of arm disorders didn't change with forearm support use, but pain in the right arm dropped by nearly three-quarters of a point, he said.
"The forearm support probably reduced the shoulder load so that the neck and shoulder weren't doing as much work. Also, it probably kept the wrist in a more straight and neutral position," he said.
Use of the trackball had mixed results. It significantly reduced left upper extremity pain and disorders, but had no effect on right upper extremity disorders. These findings were unexpected, the researchers said, since 98 percent of the participants used the mouse with their right hand.
The researchers also did a return-on-investment analysis to see if the forearm support would make financial sense to employers. The average cost per board is around $100, said Rempel. The study found that employers would recover these costs within about 10 months of purchasing the boards.
Dr. Mark Melhorn, a clinical assistant professor at the University of Kansas School of Medicine-Wichita, said, "It is reasonable to make a small investment in an arm or wrist rest if it makes the user feel comfortable. The cost associated with muscle pain can be high and the intervention cost is low."
The study also recommended other ergonomic measures to help relieve computer-related injuries. These include maintaining an erect sitting posture; a chair height that allows the thighs to be parallel to the floor; adjusting the arm support and work surface height so the forearms are parallel to the floor; a mouse and keyboard location that minimizes reach; adjusting the monitor height so its center is about 15 degrees below the visual horizon; and taking scheduled breaks.
Melhorn added that such steps are only half the solution, though, since people develop musculoskeletal disorders and muscle pain due to a combination of individual risk factors, such as age, gender and genetics, and their physical activity at home and in the workplace.
"If you take 100 people and put them in front of a computer, only 14 percent will develop muscle pain," he said. "If just the job caused these injuries, then 100 percent would have the muscle-pain condition. So you need to improve the person and the workplace. This study only addresses a small spectrum of these causes, but it's a good start in the right direction."
For more on how to make your computer workstation safe and comfortable, visit the Occupational Safety and Health Administration.