Pronation
Years ago I realized that much of my hand and wrist pain came from the pronation (wrist rotation analogous to roll of an airplane) required to use my Trackman Marble. I kludged a stand of sorts to tilt the TM by about 45 degrees and I felt much better. Since then there have been a couple of trackballs with this sort of tilt built in -- among others, the Logitech Trackman Ergo has an optional stand -- and recently I've been using a Kensington Pro Fit Ergo Vertical Wireless Trackball (https://www.kensington.com/en-gb/p/products/control/trackballs/pro-fit-ergo-vertical-wireless-trackball/). It tracks well, it's easy to pop the ball to clean out accumulated crud, and my only problem has been its tendency to switch itself from WiFi to Bluetooth once in a while. (I suppose I'm brushing one of its innumerable buttons by mistake, but I now know which button to push to unswitch it.) The Kinesis Advantage has eliminated the pronation pain I had from flat keyboards and the tendonitis that almost kept me from working thirty years ago hasn't come back.
Biting the hand that feeds IT
