“While the amount of movement on a particular key is exactly the same in the keyboards we used, the problem is the large number of times you have to go to the top and bottom rows using QWERTY,” said Dr. Rick Robertson of the University of Pittsburgh Medical Center. “As soon as you move from the home row, you increase the angular motion of the fingers and sliding motion of the tendons, which increases the potential for CTDs.”
To get finger motion measurements, the researchers videotaped three individuals with three cameras using the standard QWERTY keyboard and two others that were designed to allow the individuals to do the majority of keying on the home row.
DVORAK was developed by University of Washington researchers August Dvorak and William Dealey in the 1930s in response to the fatigue associated with typing on typewriters.
ASINREDHOT by Finger Relief of Seminole, OK, was developed in 1992. Unlike DVORAK layout in which practically every key was relocated, ASINREDHOT (the marketing name, now interossei) moves only 12 keys to make learning easier. The letters on the home row actually spell out ASDEIHOTLNR.
“Our hypothesis was that excessive tendon motion in the carpal canal induces trauma to the nearby tissues,” said Robertson. “It appears that alternative key location is a good way to reduce finger and tendon motion.”
While the researchers admit a study involving only three people makes it difficult to provide definitive statements, Robertson suggested that tendon motion could be reduced by careful consideration of where the most commonly used keys are located.
He also suggested that general acceptance of an alternative key layout combined with ergonomic improvements to workstations would have a positive impact on the incidence of carpal tunnel syndrome and cumulative trauma disorders.
Robertson, along with fellow researchers Margaret Flannery of California State University, Sacramento and Dr. Rory Cooper of the University of Pittsburgh, plan to expand the project to increase the number of subjects. They would also like to perform a pain and injury comparison of individuals retrained on alternative keyboard layout and a group using the QWERTY layout.
CTD NEWS APRIL 1995
Reprinted by permission of CTDNews