Elements of Ergonomics Programs A Primer Based on Workplace Evaluations of Musculoskeletal Disorders

The site was a cabinet manufacturing company in which basic work processes involved sawing rough lumber, planing cabinet panels and parts, sanding and painting, assembly, and packing and shipping. A total of 17 jobs representing one full production of a kitchen cabinet were first screened on the basis of job descriptions and walk-through observations for risk of both musculoskeletal disorders and traumatic injury. Five job tasks (three lifting tasks and two pushing and pulling tasks) were selected for more in-depth analyses because of their linkage with excessive back strain and sprain reports among the workers. Videotapes and still photos were taken of the job tasks, along with workstation measurements. (NIOSH protocols for analyzing videotapes of job operations are described in Tray 5-H of the Toolbox.) Frequencies, weights, and heights of loads lifted were noted together with measurements of initial and sustained push forces. Applying the NIOSH 1980 lifting equation formula for defining lift weight limits and the Michigan 2-dimensional static strength prediction program showed that the three lifting jobs presented conditions warranting control actions to reduce risk of overexertion or back injury. (Information about these two techniques is included in Tray 6 of the Toolbox.) Initial and sustained push forces for the other two jobs were rated against maximal acceptable values reported in the literature for 50% of the male and female population. One of these two tasks (pushing stacking bunks) exceeded these values and was judged potentially hazardous; recommendations for risk reduction were offered [HETA 88–384–2062].