So why would you use an ergonomic mouse? The traditional computer mouse was not designed with ergonomics in mind and can lead to a condition known as repetitive strain injury (RSI). It's sort of an umbrella term used to describe a variety of symptoms and it's the most common computer-related injury. This is where ergonomic input devices come into play. The basic idea here is that an ergonomic mouse can help to prevent future injury or ease existing pain. MX is the flagship mice series from Logitech and the MX Vertical is pitched as the firm's most advanced ergonomic mouse.