Wiesbaden - All of a sudden your arm feels heavy as lead and starts to tingle. You tend to drop objects more frequently than you used to. If you are a frequent computer user, mouse arm may be the culprit. "Mouse arm is a modern form of classical tennis elbow," explains Jan Bernholt, an orthopaedist from Duesseldorf. Small movements that are constantly repeated can lead to ailments in the upper and low arm. An ergonomic workspace can help prevent this.
Mouse arm is a manifestation of Repetitive Strain Injury (RSI), and can be caused not only by working with a mouse but also through other actions that overload the hand and arm area. "Your arm feels funny, the muscles cramp or you feel a pull or prickling in the arm," says Professor Hardo Sorgatz from the Institute for Psychology at the Technical University of Darmstadt.
The monotonous stress first causes small tears and strains in the fibres, although these then regenerate quickly, Sorgatz explains. If the work situation is not improved, however, tendonitis, permanent loss of strength and chronic pain when moving - or even remaining still - can follow. At that point it is imperative that a new movement patterns be introduced.
"And the brain needs to learn that those movements are not marked by pain," Sorgatz notes.
Anyone who sits tensed up in front of the PC, repeating the same motion again and again, is not using a broad range of motion. "Frequent breaks are important, at least every two hours," Bernholt, says. "The essential thing is movement at your workspace," says Gregor Mertens from the Institute for the Promotion of Occupational Health (BGF) in Cologne. "That means standing up once in a while when working or breaking up all the sitting by visiting with colleagues or going to the printer."
There are also specific exercises to loosen up the hands, lower arms and shoulders: "Stretch out your arms and make a fist and then release. Spread and the close your fingers and shake out the hands, which promotes circulation," Mertens says.
The office workspaces should fulfil ergonomic criteria as much as possible. "Wrist wrests in front of the mouse and keyboard can help, and ergonomic keyboards with buttons oriented slightly toward the inside provide a proper working angle," Mertens says. The angle between the upper and low arm should be 90 degrees, and the precise positioning of the mouse is important: At 43 centimetres, keyboards are almost always wider than the shoulders. "If the mouse is beside it, then it is automatically beyond the natural shoulder width," explains Rolf Ellegast, director of the Ergonomics Research Group at the BG-Institute for Occupational Safety and Health (BGIA).
To avoid improper positioning, the mouse should be positioned roughly at shoulder width. The mouse can also be operated in many ways. The movement can come through the wrist, the lower arm or even the shoulder. "That works different muscle groups," Ellegast recommends. Some commands can be given using the keyboard instead of the mouse. Double clicks can be programmed into the mouse's middle button, and specific key combinations can be designated for frequently used phrases. A joystick or input stylus can also be used in place of the mouse.
