The 3M EM500 Ergonomic Mouse looks so much like a joystick that we initially thought we'd be moving the mouse around by tilting the mouse's vertical grip. But looks can be deceiving: the EM500 Ergonomic Mouse functions by dragging across the desk surface, just like a traditional mouse. The unique vertical grip is designed to keep your hand, wrist, and forearm in a neutral upright position--much like a handshake--that eliminates the forearm twisting that is blamed for some repetitive stress injuries. (Of course, if you are experiencing repetitive-stress-related discomfort because of using your computer, you should seek out the advice of a doctor in addition to making adjustments to your workstation.)
Aside from its unusual design, everything about the EM500 Ergonomic Mouse is simple. To use it, just plug it into your computer's USB port (or a PS/2 port using the included adapter)--no software is required, though we had to increase the mouse sensitivity in the Control Panel to account for the unique shape. You navigate by resting your hand on the base, loosely grasping the vertical grip, and sliding your hand from side to side to move the cursor. There are just two buttons on the EM500: a rocking thumb button and a broad button at the fingertips. The former functions as traditional left- and right-clicks (press down for left-click, up for right-click), while the latter functions as a center-click and scroll key. Unfortunately, these buttons are not programmable.
Once we'd adjusted the sensitivity so the cursor traveled farther with less movement, we found the mouse's optical sensor very accurate and sensitive. We were surprised at how quickly we adapted to the unusual mouse shape. We were also surprised that we used the EM500 Ergonomic Mouse as our primary mouse for nearly a week without pain--quite a feat, considering we've been mousing left-handed for years, and a few hours with a traditional right-handed mouse usually results in a dull ache. Of course, we'd prefer to have a left-handed version, but sadly 3M does not offer one.
The EM500 Ergonomic Mouse is available in two sizes, small/medium and large, to suit different users. Both sizes are widely available at prices as low as $40--a decent price for a comfortable mouse with simple functionality.