Laptop PCs are convenient, but can also become an ergonomic nightmare by causing neck pain and other injuries.

LOS ANGELES, May 31 (Xinhuanet) -- Laptop PCs are convenient, but can also become an ergonomic nightmare by causing neck pain and other injuries, the CNET News reported on Tuesday quoting doctors.     

    Laptops were never designed as a replacement for a desktop computer, said Alan Hedge, director of the Human Factors and Ergonomics Laboratory at Cornell University. The idea was portability for occasional use, but never intended to be a machine you would work at for eight hours a day, 52 weeks a year.

    The main problem with laptops is that the screen and keyboard are so close together. Without the aid of peripherals, laptop users have two choices, to cramp their neck down to view the monitor, or to elevate the machine to eye level, neither of which would win them any points for posture. And the wrists lose regardless, because the keyboard is so small, leading to awkward hand positioning.

    "These are all recipes for disaster for your body, and your musculoskeletal system especially," said Nicholas DiNubile, an orthopedic surgeon.

    Laptops can cause other physical woes. People have been burned by the heat the machines generate. The temperature issue can also cause fertility problems in men who place the machines on their laps for prolonged periods. Frequent travelers can put strain on backs, hands and shoulders by lugging a laptop around.

    More than 9,200 US non-government workers reported missing a day or more of work because of typing and keyboarding-related injuries in 2003, according to figures from the US Bureau of Labor Statistics. Ninety-two percent of those cases were associated with worker motion or position. More than a third those workers missed over a month of work because of their injuries.

    For notebook computer use, such statistical information on injuries is scarce, but doctors report a steady stream of new patients who've overdone it on the machines. That's not surprisinggiven the boom in laptop sales. Nearly 49 million notebooks were sold in 2004 worldwide, almost double the number in 2000, according to market researcher IDC.

    Another reason people are spending more time on laptops is thatthey've become mobile entertainment centers complete with DVD players, bigger screens and more-powerful processors. These machines, though often heavier and less portable than previous types, will dominate the laptop scene in the future.

    Many laptop-related injuries can be avoided. The use of peripherals such as docking stations, separate keyboards and mice is probably the easiest way to avoid neck and shoulder trouble, doctors said.

    These add-ons let users adjust monitors to eye level while keeping arms and shoulders in a natural position. Several companies offer laptop stands that prop machines up to desired height.

    The ideal height of the monitor is about 20 degrees below horizontal eye level, or 20 centimeters below eye level at a viewing distance of about 50 centimeters, doctors advised.

    Special pads and trays, some with fans, can reduce risk of burns and other heat-related problems. But these items can be unpractical for travelers. Their ergonomic benefit may be offset by the strain of hauling them around in a shoulder or handbag.

    Lifestyle choices and work habits are also critical to warding off computer-related ailments. Taking short breaks every 20 to 30 minutes, stretching, eating healthy and exercise all reduce the risk of injury with any type of computer. Knowing when to shut off the devices and call it day is important too, especially with portable machines. Enditem