Can Two-Finger Typing Lead To Carpal Tunnel Syndrome?
November 13th, 2006 | Published in RSI in the News | 1 Comment | Tags: keyboards
In an article on MedPage Today (Two-Finger Typists at Risk for Carpal Tunnel Syndrome), Managing Editor Peggy Peck argues that it can.
“The time-honored “hunt-and-peck” approach to typing at a computer keyboard, using just the index fingers, may trigger a cascade of events that climaxes with carpal tunnel syndrome,” she writes.
In an article in the November issue of Plastic and Reconstructive Surgery, Kai-Nan An, Ph.D., a professor of bioengineering at the Mayo Clinic, suggests that “two-finger typing is likely to cause a shearing injury to subsynovial tissue in the wrist”.
“The subsynovial tissue consists of a number of layers, much like the layers in a puff pastry. These layers of fibrous bundles run parallel to the tendons and are connected to both the flexor tendons and the synovial membrane. When fingers are moved, both the tendons and this subsynovial tissue are stretched, but some movements cause maximum stress. For example using index fingers to type while keeping the other digits extended, results in maximum stress on the tendons and tissue - enough stress to shear the subsynovial tissue from its moorings.”
“Two-finger typists can reduce stress on the subsynovial tissue by curling the other fingers when pecking away with index fingers,” Dr. An said.
The researchers hope to develop ultrasound tests that could be used to scan for signs of early damage, as well as to design hand or finger exercises to reduce the stress caused by stretching the tendons and subsynovial tissue.

January 4th, 2007 at 8:11 am (#)
I type with two fingers, and have done for years. I have also become pretty good at it - so that on a roll, I can type as fast as most people using full hands.
For some years I have been asking (in the UK) for someone to teach me to type properly as I have a lump on my wrist and experience pain whenever I type - both of which I am convinced are largely caused by this bad habit.
Unfortunately, no-one seems to offer typing training aimed at relieving RSI.