3m Wireless Ergonomic Mouse Em550gps Review

I should now modify the review and say that though it worked well for a while, this mouse ended up aggravating my specific condition (DEQUERVAINS TENDONITIS). The back and forth movement of my thumb to press the "mouse" buttons on top of the "joystick" caused enough irritation to this condition that I finally had to have tendon release surgery in August of 2010. Others experiences may be different, however. I put off writing this review until I had adequate time to use this mouse in all different situations. I purchased this mouse in October 2009 (the large model, item model number EM550GPL). I had developed a very painful Repetitive Strain Injury (RSI)in my right hand and arm from heavy mouse use in particular the constant use of the roller wheel and the clickclickclicking of the mouse buttons. I am a medical librarian and use my computer all day for long stretches of time. However, I dont play video games though that require much more clicking than office work. I considered and tested quite a few "ergonomic" mice. Most of them merely changed the users hand position, but still required clicking buttons with the index and middle fingers. I am mostly pleased with the mouse, and I will address specific features, both good and bad, in hopes that this will help someone else with a similar condition. Comfort 5 stars Compared to other ergonomic mice I have tried this one is very comfortable for extended use. Though it looks like a joystick, the handle doesnt move. When grasping the mouse handle the users hand is at about a 45 degree angle. Left and right button clicking (for Windows users) is accomplished with the users thumb on a rocker button at the top of the handle. The thumb is much stronger and has more leverage for short movements than the other fingers, and the movement of the thumb is very small. I have only encountered thumb pain after performing tasks that involved constant clicking for over an hour. If the user takes short breaks (which is recommended for A