This mouse is clinically proven to alleviate pain and discomfort of repetitive stress injuries in the hand, wrist or arm associated with the use of traditional mice - which requires forearm pronation and may cause pressure on the wrist and carpal tunnel area. The 3M Ergonomic Mouse has earned an ease-of-use commendation from the arthritis foundation for its patented, vertical grip design that keeps your hand and wrist at a neutral angle, while the mouse works as a regular optical mouse. Grip the handle and rest your hand on the base.