An ergonomics program to control work-related cumulative trauma disorders of the upper extremities.

Abstract

The effect of an automotive plastics plant's 20-month ergonomics program was evaluated. Control measures were implemented through an in-plant Task Force composed of management, labor, medical, engineering, and safety personnel from the plant. Ergonomic stresses and morbidity for upper extremity cumulative trauma disorders (CTD's) were evaluated. CTD job risk factors were identified from videotapes and presented to the Task Force for evaluation and action. New jobs were videotaped and studied after the program began, but were not correlated with health status changes. Ergonomic consultants presented 64 recommendations to reduce CTD job stresses: 51 recommendations for original jobs (33 percent were considered and 18 percent implemented) and 13 for new jobs (85 percent were considered and 46 percent implemented). The original jobs tended to have more administrative controls applied; newer jobs had more engineering controls applied. Worker input and acceptance of job changes appeared to assist implementation of recommendations for both original and new jobs. To evaluate changes in ergonomic CTD stresses, jobs were videotaped at the beginning and end of the program. No significant differences in work repetition or posture in the overall study population were found. However, there was a reduction in force for the left h and (p $<$ .05) and the right h and (p $<$.076) due to sharper knives and fewer trimming motions from press operators, improved parts production and improved design. Morbidity patterns were determined from three work history interviews and physical examinations administered to 416 production workers at 7 month intervals. There was a 10-30 percent reduction in CTD reporting over the control period, specifically, for the wrists and h and s. However, these changes could not be attributed to the program because of worker mobility, difficulty in precise health measures, lack of medical diagnosis, and changing CTD symptoms over time. Although this ergonomics program shows promise in identifying and controlling occupationally related CTD's, it may be most beneficial as a prevention strategy during work station development and where worker input is incorporated into the design process.