Tools for Exposure Assessment of Physical Risk Factors of VDT Workers.

摘要

In order to understand the high prevalence of work-related musculoskeletal disorders in the modern office, we aimed to develop specific exposure assessment tools and methods to measure physical risk factors of computer workers at their own workstations. Specifically, we pursued three goals. First, we validated a computer interaction monitor (CIM) software program in order to determine the optimal cutoff time that will capture both active interactions, such as measurable keyboard and pointing device events, and passive interactions, such as reading documents from the visual display terminal. Such CIMs provide detailed measurements of the frequency and duration of exposure. We monitored 20 individuals at their own workstations for four hours. During this time we recorded their computer interactions with both a CIM program installed on each individual's computer as well as a videotape of both their hands relative to the keyboard and mouse, and their eyes while viewing their computer display. Second, we developed specific measuring devices to quantify keyboard force and mouse force in the modern office. Third, we completed a study to compare and validate various sampling strategies for determining the intensity of biomechanical factors in the field. In the field, we measured 20 workers for 6 hours on each of four days. We measured both keyboard force and wrist posture while individuals completed both their own work and brief periods of simulated work (~5 minutes). In addition, each subject completed the simulated work in a laboratory setting under two conditions: in a set-up that emulated their own workstation, and at appropriately adjusted workstation. All phases were successfully completed.