Traditional mouse designs cause a twisting of your forearm to place the palm of your hand in a horizontal position over the mouse. Combine this with repetitive clicking of your index finger and discomfort may set in.
The idea is to place the hand in a relaxed, neutral position so that the muscles and tendons of the hand can work in their comfort zone.
The benefits of any ergonomic mouse are increased when using a flat, gel mouse pad. Most of the roller bar technologies you will see have a built-in wrist pad.
The Best of the Best section begins with the newer “rolling bar” alternative mouse concepts and includes a mouse with several sizes for lefties and righties!