The more you click using your computer's mouse, the greater the chance of suffering from pain, swelling, numbness and other problems in the hand, wrist, neck and shoulder, two teams of Danish researchers reported at a meeting this week.
In one study, Dr Chris Jensen and colleagues from the National Institute of Occupational Health in Copenhagen found that workers who used computers for more than two-thirds of their work time had a higher risk of developing hand or wrist problems.
However those who worked in front of a computer almost all day and used the mouse at least half the time had a four-fold higher risk of problems than those who used the computer the same amount of time but used the mouse only a quarter of the time.
The findings come from a survey of nearly 3,500 workers at 11 Danish companies, with follow-up about a year and a half later. “The problem is not only the mouse, but performing repetitive tasks,” Jensen said.
In a second study, researchers from the Odense University Hospital and Glostrup and Herning hospitals found that those who used the mouse for more than 30 hours per week had as much as an eight-fold higher risk of developing forearm pain, double the risk of moderate to severe neck pain and triple the risk of right shoulder pain. Neck and right shoulder symptoms started to become evident after more than 25 and five hours of weekly use, respectively.
The findings come from a survey of nearly 7,000 technical assistants and machine technicians, with a follow-up one year later. Certain professionals are particularly at risk, the researchers note.
“Computer-assisted designers use the mouse almost all the time,” co-author Lars Brandt of Odense University Hospital said. Having a demanding job seems to aggravate the problem, he added.
Jensen said a variable pattern of mouse and keyboard use can be considered the best combination from an occupational health perspective. Other measures have uncertain effects. Around 80 per cent of Danish workers use traditional instead of newer “ergonomic” mouse devices, but none of the studies examined differences between users of either type of mouse.
“My impression is that it does not really matter so much which device you use. I do not believe that you can invent a device capable of solving these problems,” Jensen said. “You could try some preventive exercises instead, but I think the best thing....is that they keep you away from the mouse or the keyboard while doing them.”
Both studies were presented at the 27th International Congress of Occupational Health.