This mouse is clinically proven to alleviate pain & discomfort of repetitive stress injuries in the h&, wrist, or arm associated with the use of traditional mice-which can pronate the forarm & wrist & typically presses the wrist & carpal tunnel area against the desk. The 3M Ergonomic Mouse has a vertical grip design that keeps your hand & wrist at a neutral angle, while the mouse works as a regular optical mouse.