Bigger Mouse, Not Better Mouse Trap, Could Help Wrist

New research from Cornell University suggests a new way for computer users to avoid wrist damage.

A study conducted by Alan Hedge, a Cornell professor of ergonomics, compared how people responded in two-minute sessions to a basic Microsoft mouse with the familiar raised bulge that fits under the palm and a lesser-known variant called the “Whale.”

The Whale mouse is a $99 device developed by a company called Humanscale in New York and befitting its name, is at least an inch longer than the Microsoft mouse and can be extended up to another inch for larger hands. Hedge said he chose the Whale because it was the largest mouse on the market, and he wanted to find out if a larger mouse might keep people from extending their wrist beyond a neutral, relatively flat position.

The answer, Hedge found, was yes. He analyzed the wrist movements of 12 men and women. Each wore sensors to track wrist extension-the position of the wrist when the hand is tilted upward while the lower arm is parallel to the ground.

Many doctors believe that carpal tunnel syndrome is exacerbated when the wrist is continually moved out of its neutral position.

“You have a problem,” Hedge said, “when the extension angle goes beyond 15 to 20 degrees.”

People in the study who used the larger mouse maintained an acceptable wrist angle of less than 15.5 degrees twice as often as with the smaller one. The larger mouse required arm movement

New York Times News Service
Published Monday-January 24, 2000