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. Relevance to industry Awkward working postures can lead to discomfort or injury. This study evaluates the effectiveness of a joint, plant-level labor-management program in controlling worker exposures to awkward postures.

Design of strategies to assess lumbar posture during work

“…In most surveys, the principal parameter of exposure is the angular position of the trunk, usually expressed on a categorical scale, even when real-time registration of angular trunk position took place. A popular standard is the division into various regions representing neutral, mild, and severe flexion, lateral bending or rotation (Genaidy et al, 1994;Keyserling et al, 1993). Marras et al (1993) also focused on other exposure parameters, demonstrating that average twisting velocity (deg/s) as well as maximum sagittal flexion (degrees) and maximum lateral velocity (deg/s) were important factors to distinguish between high-risk and low-risk jobs for back injuries among workplaces involved with repetitive manual handling work.…”

Ergonomic stressors and upper extremity disorders in vehicle manufacturing: cross sectional exposure-response trends.

“…1 Evidence exists as to the ergonomically stressful features of many jobs in vehicle assembly as well as the manufacturing stages that precede final vehicle assembly. [2][3][4][5][6][7][8][9][10][11][12][13][14] Several epidemological studies have documented the musculoskeletal disorders associated with the demands of work in this industry. 8 12-19 However, publications are still few relative to the large variety of jobs and exposures and the size of the workforce involved.…”

A perspective on work system analysis: classification and evaluation of methods

“…Burnette and Ayoub (1989) and Burnette (1990) developed a computerized model (CTD-123) to predict the relative risk of developing cumulative trauma disorder symptoms for the major anatomical joints. The Ontario M inistry of Labour (1981,1988), Keyserling et al (1992), RULA (M cAtam ney and Corlett 1993) and Keyserling et al (1993a ,b) all used the checklist approach to evaluate physical stresses with varying degrees of success. Checklists serve as a useful preliminary screening technique; evaluations can be performed quickly and with relatively little training.…”

“…These techniques, however, have not been widely applied in industry owing to their complex an d labour intensive nature. In order to facilitate a more practical analysis process, many researchers designed checklists to assess ergonomic hazards, mainly focusing on physical aspects (Lifshitz and Arm strong 1986, Ramsey et al 1986, Keyserling et al 1992, 1993a. Although they can function as eOE ective rapid screening tools, most checklists produce limited results in that they are narrow in scope and provide incomplete data for work redesign.…”