Robust Ergonomic Design of a Video Display Terminal Work Station in Virtual Environment

In most industrialized countries, the costs of compensation for musculoskeletal disorders accounts for more than one half of all workers’ compensation costs (Norman and Wells, 1998). Several reviews have evidenced that a strong work-related component exists for many upper limb and low back pain cases (NIOSH, 1997; Fogleman and Lewis, 2002). In particular, there is a growing recognition that office tasks, especially those associated with Visual Display Terminal (VDT) can lead to musculoskeletal disorders. There are hundreds of ergonomic interventions described in the scientific and lay literature (Park et al., 2000), unfortunately most of them lack formal evaluation. Research on ergonomic interventions is very difficult to do for many reasons that include: a work environment that changes more rapidly than the time it takes to complete a well designed study; the natural change in the work place that inhibits maintenance of proper control groups for the duration of a study; the high costs of studying sufficiently large groups to obtain acceptable statistically significant comparisons between intervention and control groups; inducing companies to get involved in this type of research given inevitable work interruptions. Obviously, it is important to identify ergonomic interventions that are effective in reducing the incidence of work-related musculoskeletal disorders (WMSD), their personal costs and the monetary costs associated with them (Norman and Wells, 1998). A current challenge for research is to involve statisticians, experts in the field of ergonomics, designers and project engineers in the formulation of methods and procedures to support the design and the analysis of experiments in virtual environment. In this paper, the Authors present the first results of a research aimed at minimizing discomfort of a new VDT workstation, through the application of parameter design methodology. In order to discriminate among various design solutions, a comfort index based on a loss function is applied. In this way, the optimal VDT workstation design – in terms of minimum discomfort for VDT operator in static posture – can be found. Besides, in order to improve the posture assumed by operators with different anthropometric characteristics, abacuses for adjustment of a working seat to Visual Display Terminal (VDT) are proposed. The proposed approach is based on the use of digital human models and some posture and task analysis toolkits implemented in a software for ergonomic simulations (Classic Jack by UGS)