The effectiveness of a joint labor-management program in controlling awkward postures of the trunk, neck, and shoulders: Results of a field study

Abstract

Awkward working posture at the trunk, neck and shoulders may be caused by a number of factors, including: workstation layout, visual demands of the job, design of equipment and tools, and work methods. Because awkward posture is a recognized risk factor for the development of fatigue, discomfort, and/or disability, the elimination or reduction of awkward work posture is a major objective of many workplace ergonomic programs. A longitudinal study was undertaken in a large automotive corporation to evaluate the effectiveness of a participative union-management program in reducing work-related musculoskeletal injuries and disorders, including those caused by awkward postures. Following a one-week training program, plant personnel used checklists to evaluate posture on 335 jobs in selected departments at four participating plants. The results of these evaluations were used to develop an intervention program in each plant for controlling awkward postures. To evaluate the effectiveness of the intervention programs, a subset of 151 jobs was tracked by an independent team of university-based ergonomists who performed comprehensive posture analyses at six-month intervals. The independent evaluation found that the labor-management teams were generally effective in reducing awkward postures at the trunk and shoulders. There were significant decreases in the time spent in awkward trunk and shoulder postures as a result of interventions that were implemented during the study. However, the teams were not effective in controlling neck postures as the frequency of awkward neck postures actually increased over the course of the study. Most of the successful intervention projects involved modifications to workstation layout in order to reduce or eliminate low, far, or overhead reaches associated with awkward trunk and shoulder postures. Interventions that required changes in product design or major changes in manufacturing processes were generally not observed during the monitoring period.