Totally agree. I've been using a Logitech Trackman trackball for about 10years now. During the periods when I wasn't using it I'd get wrist.forearm pain and bursitis on the wrist (I have plates there from a car accident). Stretching is still important but the trackball is a major leap forward.

If you have to use a mouse, please don't use an Apple mouse. They are generally far too small and don't provide any support. I'm still amazed that a company which does great hardware aesthetics completely fails to understand ergonomics.