Vibrating mouse prevents computer-related injuries

Cornell University researchers are studying several innovative products, such as a massage chair and a vibrating mouse, to determine whether they may help prevent back and other problems that result from sitting in front of a computer for long periods of time.

Alan Hedge, professor of design and environmental analysis in the university's College of Human Ecology, has taken up this study at a time when the incidences of computer related injuries have increased in youngsters in their twenties.

"One-third to one-half of all compensatory injuries are repetitive-motion injuries associated with office-type work," says Hedge.

Back injuries, adds the researcher, also account for one-third of all workplace injuries.

Hedge says that most of these injuries were associated with heavy lifting a decade ago, but their biggest cause nowadays appears to be sitting in front of a computer all day.

He says that problems like carpal tunnel syndrome-a medical condition in which the median nerve is compressed at the wrist, leading to pain and muscle weakness in the forearm and hand-were usually reported by people in their late 30s to early 40s during the early 1990s.

However, he adds, the average age of onset of such conditions has dropped to the mid-20s these days.

"Now kids are using computers at age 2, so by the time they enter the workforce they'll already be primed for injuries. This is very serious because an injury can become life-changing; carpal tunnel, for example, is not curable. They'll have to manage this chronic condition for the rest of their lives," Hedge says.

Just to address these concerns, Hedge adds, his Cornell Human Factors and Ergonomics Research Group is studying innovative products.

The researchers have so far studied a vibrating mouse to see whether it could prevent upper extremity musculoskeletal disorders in computer users by signalling people to take their hand off the mouse to avoid overuse.

Reporting their findings at the Human Factor Ergonomics Society Annual Meeting in October, they revealed that though the subjects did remove their hands more often with a vibrating mouse than with a conventional mouse, they tended to hold their hand just above the mouse.

"This position is potentially more detrimental because of a potential increase in static muscle activity required to hover the hand," Hedge said, concluding that people should rest their hands on a flat surface when they felt the vibration.

In another experiment, the researchers examined the efficacy of an undulating chair whose seat made a continuous messaging, wavelike movements in alleviating back pain in people whose pain increases when they are seated.

Although their findings were mixed, Hedge and graduate student Erin Lawler concluded that the movable seat was a concept with promise, particularly for individuals with back problems.

"Everything we do can be summed up in the phrase: Good ergonomics is great economics. More than 90 percent of a company's costs are people costs, so making small investments in improving the workplace by using good ergonomic products pays huge dividends," Hedge says.