Goldtouch Comfort Mice
The Goldtouch Comfort Mice were designed to put user's hand in a neutral position, taking the pressure off of the hand, wrist and forearm. In this position, the hand is positioned so the fingers are slightly cupped and splayed, with the thumb forming a "C" shape with the index finger. This position is easily observed in a weightless environment, for example, while the hand is relaxed and suspended in a bath or swimming pool.
This mouse is a favorite and most users can't imagine going back to a regular non-ergonomic mouse after trying it. Give it a try and see for yourself.