Effect of chair design on ratings of discomfort.

The purpose of this study was to determine if ratings of discomfort differ over time between two ergonomic chairs of the same approximate cost. Twenty participants from a metropolitan university sat on two types of ergonomic chairs for 90~minutes in each of two sessions while performing typing, reading, and writing tasks. Repeated measures three-way and two-way analyses of variance were used to examine the effect of the ergonomic chair design on rating of discomfort. Data were collected using the General Comfort Rating Scale (GCRS) and the Body Part Discomfort Rating Scale (BPDRS), which were administered at 0, 30, 60, and 90 minute marks of each session. The results revealed: 1) discomfort was not related to the type of chair, 2) discomfort increased over time, 3) discomfort was influenced by the task performed while sitting, 4) discomfort level decreased when switching between different chairs, and 5) most discomfort was reported in the low back and lower arms.