Joint damage caused by rheumatoid arthritis (RA) can lead to difficulties in typing and can force people to seek alternative—but potentially more destructive—ways of putting their fingers to the keyboard, according to researchers.

Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.

People who suffer from RA often experience work limitations. Without adequate treatment, some 60% of people with RA are unable to work 10 years after the onset of their disease. The Census Bureau reports that nearly 215,000 professionals are employed as typists. For those with RA whose work depends on touch typing —typing based on knowing the location of keys on a keyboard, rather than using sight to find the keys—understanding the mechanism of hand motions during touch typing may provide insight into how people with RA can safely and efficiently type.

In a study funded in part by the American College of Rheumatology (ACR) Research and Education Foundation, Atlanta, researchers recently set out to determine the effects of structural deformities on the postures and motions of the hands and wrists during touch typing. They hypothesized that touch typists with structural deformities caused by RA would have significantly different typing postures, motions and speeds than those without structural deformities. They studied 33 participants with RA to determine if their hypothesis would hold true.

Researchers videotaped each participant and studied their postures and motions while typing. Additionally, each participant’s video was rated by a certified hand therapist for the presence of visual structural deformities–damage to varying joints, which causes a visible change in the shape of the hand. Finally, typing postures and motions were rated by two raters trained in the use of the Keyboard-Personal Computer Style Instrument–an observational instrument that documents postures and actions of keyboard users.

The 22 participants with structural deformities were compared to those without. Researchers found that participants with structural deformities due to RA showed more whole hand and wrist motions—commonly called the ‘hunt-and-peck’ method of typing—than those without (64%) structural deformities. These participants used this style of typing to activate the keys rather than individual finger motions. Finally, researchers found that significantly fewer participants with structural deformities used a wrist support, and there was no significant difference in typing speed between the two groups of participants.

Based on these findings, researchers concluded that structural deformities can affect the typing styles of touch typists with RA. Moreover, biomechanical research that examines the degree to which different postures and actions increase or reduce mechanical stress on joints suggests that alternative typing strategies—such as the hunt–and-peck style, floating the wrists, using fewer fingers, and keeping fingers straight rather than curved—may increase existing problems by putting additional stress on already affected joints.

“This research suggests that as people develop changes in the structures of their joints, they may find alternative ways to accomplish tasks,” says Nancy Baker, ScD, MPH, OTR/L, associate professor at the University of Pittsburgh, Pittsburgh, Pa, and lead investigator in the study, in a statement. “The alternative methods are often to change their physical performance; for example they may slow down, change their postures, or move differently. While changing their performance may allow the continuance of doing the task, it may place them at risk for other problems. Thus, touch typists with joint damage may shift to techniques that place biomechanical stress on their already weakened joints.”

For touch typists with RA, researchers offer alternative suggestions to ensure proper working hand and wrist posture including using an ergonomic keyboard and moveable wrist support and/or redesigning your computer workstation to better suit your individual typing needs.

“While altering tasks is almost certainly necessary in any disease or injury that causes physical changes, there are ways to make changes that are less likely to place a person at risk,” Baker said. “It is often better to change the environment to support the person doing the task than it is to change the performance itself.

[Source: American College of Rheumatology]