The Effect of Six Keyboard Designs on Wrist and Forearm Postures

There is increasing evidence that alternative geometry keyboards may prevent or reduce arm pain or disorders and presumably the mechanism is by reducing awkward arm postures. However, the effects of alternative keyboards, especially the new designs, on wrist and arm postures are not well known. In this laboratory study, the wrist and forearm postures of 100 subjects were measured with a motion analysis system while they typed on 6 different keyboard configurations. There were significant differences in wrist extension, ulnar deviation, and forearm pronation between keyboards. When considering all 6 wrist and forearm postures together, the keyboard with an opening angle of 12°, a gable angle of 14°, and a slope of 0° appears to provide the most neutral posture among the keyboards tested in the configuration tested. This study identifies significant wrist and forearm posture differences between 6 keyboard configurations. These findings may assist in ergonomic recommendations regarding computer usage.