A compensatory rest break system for VDT operators

Abstract

Short rest breaks at 10 or 15-min intervals are being proposed as a means to moderate health problems and discomfort associated with continuous VDT use. This laboratory study evaluated an alternative to administering frequent breaks on a regimented schedule; short breaks were not administered unless the operator's spontaneous rest pauses were insufficient. Undergraduate volunteer typists (N=38) were assigned to one of two conditions: regimented (20-sec breaks every 5 min), or compensatory (20-sec breaks every 5 min only if the spontaneous pauses did not total 20 sec). Participants entered lines of randomized upper and lower-case characters that appeared on their VDT during a 48-min work period. Mood and musculoskeletal discomfort were assessed before and after the work period, followed by a questionnaire about the break system. Performance measures included keystroke output, error rate, and correction rate (backspace use). Large pre-to-post work period differences in both mood and musculoskeletal discomfort were found. Both the number and length of computer-administered breaks decreased in the compensatory condition. Back discomfort was lower in the compensatory condition, however, no differences in performance, mood, nor acceptance of the break system were found. These results indicate that rest breaks administered on a compensatory basis during repetitive computer work can eliminate unnecessary breaks and improve well-being without being any more disruptive to work than regimented breaks.