Abstract
This study presents an evaluation of an adjustable keyboard based on subjective preference and wrist joint motion during typing. Thirty-five computer users used the adjustable split design keyboard for 7–14 days during their usual work and were instructed to adjust the keyboard to the opening angle they preferred. At the end of this period, three-dimensional motion analysis was performed to compare the distribution of wrist joint angles while subjects typed on a conventional keyboard and the adjustable keyboard adjusted to the subject's preferred angle. The mean preferred opening angle was 14°±10. The mean ulnar deviation of the subjects who selected the opening angles between 21 and 28° (n=12) decreased from 18°±5 on the flat to 14°±5 on the adjustable (p<0.05), while those who selected 0 to 10° (n=6) and 11 to 20° (n=17) split angles showed no significant differences in ulnar deviation. Mean wrist extension on the adjustable keyboard was 17°±5 and was significantly less than the 24°±5 observed on the conventional keyboard and most likely due to the presence of palm support. On average, subjects reported that the adjustable keyboard was more comfortable (0.5±0.5) (worse=−1, same=0, better,=1) in comparison with the conventional keyboard.