The reason is that the unique and patented shape of the HandShoeMouse fully supports your hand in the best relaxed position and prevents gripping and pinching, what you do when you use a standard mouse. The HandShoeMouse was developed with all complaints in mind. Support of your hand and fingers prevents gripping and pinching and your arm is supported at the ideal angle of 25-30 degrees which makes sure your forearm is completely relaxed. Instead of over-using your hand and wrist, your arm will most of the time let the optical HandShoeMouse float without any effort. The shape allows for the hand to continuously rest on the mouse body in a relaxed fashion, so there is no skin contact between your hand and the desk. As a result there is no skin irritation as caused by excessive rubbing when moving a conventional mouse. The buttons of this ergonomic mouse are positioned in line with the fingers. Only minor pressure is required to click the buttons. The thumb rest of the HandShoeMouse allows for a relaxed position and prevents excessive thumb action which can be harmful.