The Pros and Cons of Vertical Mousing Devices

No single mouse design acts as a magic wand which will address all mouse-related risk factors for injury. Although ergonomic analysis can tell us what is causing these injuries with respect to general designs, it cannot make the leap from such analyses to some universal design that incorporates all that understanding. It is up to the manufacturers of ergonomic products to focus on what problems they wish to address for their customers. Vertical mousing devices are no exception to this rule.

Vertical mousing devices, like the Evoluent VerticalMouse 4 or 3M Ergonomic Mouse, appeal to a particular group of users who experience pain when their hands are pronated, that is, twisted flat or parallel to the mousing surface in order to use the mouse. When mice were first designed, no one anticipated that high usage of the mouse in this position would cause hand injuries, but given that it does so in certain users, it was only a matter of time before manufacturers realized that a new design was needed for such individual. Thus the Vertical Mouse was born.

Apart from pronation of the hand, which is also connected with forearm twisting, some users of traditional mice developed the bad habit of bending excessively at the wrist in a side-to-side motion, a condition of the wrist and forearm usually called 'ulnar deviation'. This is allowed to happen in certain users because there is nothing naturally obstructing the hand and wrist from doing so. With the introduction of a vertical mousing device, however, which keeps the hand in a 'handshake' position, ulnar deviation is prevented because the hand rests on a surface, either the desk or mouse's own support, making such motion difficult, if not impossible, to achieve. Vertical mousing devices thus help prevent or minimize two important risk factors for mousing-related injuries: pronation and ulnar deviation. In part, the benefits of the vertical mousing device are explained by the fact that the hand and arm are closer to their natural or normal 'relaxed' positions when using such mice.

But vertical mice are not necessarily for everyone, since they, too, have limitations on all the possible injuries that can be prevented. Although pronation and ulnar deviation can be largely prevented by such mice, they are sometimes less effective in preventing another risk factor when mousing: wrist extension. Wrist extension occurs when the wrist is bent in an upwards direction, either continuously or repetitively, relative to the direction of the forearm. In a way, by solving ulnar deviation so effectively by preventing side-to-side motion while pronating, the vertical mouse can then encourage wrist extention in the 'handshake' position that mimics the side-to-side motion of ulnar deviation: this side-to-side motion in ulnar deviation is simply translated into the upward bending at the wrist in wrist extension. Unfortunately, there must be some trade-offs in replacing one mouse design with another, and so in these cases, it is strongly encouraged that the user not only adopt the mousing device that best addresses their issues but also actively change their mousing habits so that other injuries can be prevented or minimized before they develop into serious, painful injuries.

There is no doubt that vertical mousing devices are of great benefit to a large group of mouse users, and that not all users of vertical mice will develop negative side-effects like wrist extension. Properly used and with reasonable usage, vertical mousing devices have more advantages than disadvantages and play an essential part in the prevention of well-known problems like pronation and ulnar deviation. As long as one knows both the pros and cons of vertical mousing devices, good decisions can be made to ensure that one finds the most appropriate device for oneself.