Effects of a split keyboard design and wrist rest on performance, posture, and comfort.

The purpose of this study was to examine differences in experienced typists' performance, posture, and musculoskeletal pain when using a split, adjustable (SA) computer keyboard and when using a standard flat keyboard. In addition, the use of a wrist rest was examined for performance, posture, and musculoskeletal pain effects. Eighteen participants were exposed to the SA keyboard and a flat keyboard in a laboratory study of text typing for four consecutive hours on five days. The results indicated that after just 2 h of orientation and practice, the participants could perform as well on the SA keyboard as on the flat keyboard. The SA keyboard provided advantages for reduced wrist/hand pronation. There was no difference between the keyboards in the level of musculoskeletal pain reported by participants after typing. However, they reported increased pain in the back, neck, shoulders, and wrists from the beginning to the end of each of the experimental periods for both keyboards.