The purpose of this study was to evaluate the influence of computer keyboard design on hand position, typing productivity and keyboard preference. These variables were assessed on two alternative keyboard designs which were distinguished from the standard flat keyboard by their split, and from one another by the amount of lateral inclination of the right and left halves of the keyboard. The FIXED keyboard featured a split angle of 12° and a moderate lateral inclination angle of 10°. The user adjustable OPEN keyboard was used with a 15° split setting which resulted in a marked 42° of demiboard lateral inclination.

Sixteen typists, who completed 10 hours of training on both alternative keyboards, were videotaped by two camcorders while typing set texts on all three keyboards. Hand position was assessed using three dimensional video analysis. Typing productivity and keyboard preference were also investigated.

Forearm and wrist angles were significantly different (p < 0.05) among the three designs tested. Both alternative keyboards placed the forearm and wrist closer to neutral positions than did the standard keyboard. The OPEN keyboard, reduced pronation, but simultaneously increased radial deviation. The FIXED keyboard kept the forearm in moderate pronation and the wrist closer to neutral. More time was spent in neutral and moderate ranges of wrist motion when subjects typed on the FIXED compared with the other two designs. Typing productivity was reduced by 10% on the FIXED and 20% on the OPEN designs compared with the standard keyboard. No significant difference in preference was found between the standard and FIXED keyboards both of which were preferred over the OPEN keyboard.

The design that represented moderate changes to the standard keyboard (i.e., the FIXED design) preserved productivity, and was well accepted by users. The FIXED design may have a greater potential for reducing cumulative trauma disorders of the wrist because it facilitates healthy hand postures while typing.