Risk of back pain. Can a servey help? A discriminant analytic approch

Ergonomic research on back pain has evolved around development of techniques such as biomechanical, and postural analyses to assess occupational risk factors. While use of such techniques can often reveal potential for back pain in jobs before injuries have occurred, they require costly equipment and skilled ergonomists. They are also very time-consuming for non-repetitive jobs. It was hypothesized that operator knowledge of a job could be used as a source of information for identification of the risks inherent in a job. It was further postulated that a discriminant function derived from the variables measured through a survey would identify risk factors in a job, and separate jobs into groups of risky and non-risky jobs. To test this method three years' data on back pain accidents pertaining to a steel mill were analyzed to yield a set of candidate jobs. These jobs were then investigated through a survey. A significant discriminant function (p = 0.0005) was developed using the survey responses and a categorized incidence rate. A high classification accuracy showed that the survey variables could discriminate the jobs well. Job incumbents tended to over-emphasize intensity and dynamic factors and under-emphasize postural factors. The technique of discriminant analysis appears to have an exciting potential for a priori classification of all jobs on a risk continuum for management action.