Jack Dennerlein, Senior Lecturer on Ergonomics and Safety
Dates of Research:
September 1, 2008 — August 31, 2012
Specific psychosocial factors in the modern work environment have been associated with higher prevalence of musculoskeletal disorders (MSDs). However, when physical work loads are considered some of the direct effects of psychosocial factors are diminished. While several pathways may exist through which psychosocial factors impact the body and influence the onset and development of MSDs, one hypothesis, which is supported by numerous laboratory studies, suggests that increased stress originating from the work environment increases one’s exposure to biomechanical loads. Therefore, we propose to first directly measure biomechanical exposure intensities (i.e. typing and mousing forces, hand, forearm, upper arm and shoulder postural dynamics and EMG of the trapezius and the extensor carpi radialis) in 120 computer workers in the field spanning different psychosocial environments (e.g. Karasek Job Strain). We will test differences in biomechanical exposure intensities across these different environments. Since we have observed different biomechanical exposures across different computer tasks we propose to develop and validate a task-based (i.e. keyboard, mouse, and idle input device tasks) biomechanical exposure prediction model that is constructed from directly measured computer usage (tasks) and the relationships of the exposure intensities with tasks, psychosocial factors and individual factors described by the data collected in Aim 1. Finally, we will implement this model to estimate biomechanical exposures for each participant of a two-year prospective cohort of 2074 (at baseline) office workers where computer usage monitors directly measure task duration for each participant and questionnaires measure each participant’s individual and psychosocial factors. We will explore these data for relationships between biomechanics and MSDs. Public Health Relevance: This project will determine relationships between work environmental stressors including biomechanical factors and musculoskeletal disorders for the modern office. The results will influence work place design and policies through the development of new evidence-based interventions.