Identifying Less Stressful Work Methods: Computer-aided Simulation vs. Human Subject Study

Engineering analyses of work methods can help identify approaches to reduce the risk of occupational injuries; computer-aided simulation technology is effective in terms of time and cost for evaluating multiple work methods. This paper analyzed scaffolding, a common activity in construction with high frequency of overexertion injuries, through a computer simulation model (3DSSPP) to identify less stressful work strategies. A laboratory study was also performed to verify the appropriateness of using the model for scaffolding job analyses.

Seven commonly used end-frame lifting techniques were evaluated. Computer simulations of these work techniques show that considerable biomechanical stress occurs to most of the workers at their shoulders and elbows. A symmetric front-lifting at knuckle height appears to be the less stressful work technique, as determined by computer simulation. The laboratory study of the seven lifting methods, by measuring whole body isometric strength, confirmed the 3DSSPP simulation results. The simulation model is suitable for identifying less stressful work methods; the net benefit achieved from the use of the model is a reduction in testing cost as compared to traditional prototyping methodologies. The “at risk” estimation of the model seems to be conservative when compared to the laboratory experiment results. This is probably because the isometric strength of construction workers is higher than that of workers in manufacturing, which was used in the 3DSSPP model.