Comparison of five methods used to determine low back disorder risk in a manufacturing environment

Study Design. Five methods for quantifying work-related low back disorder ( LBD) risk were used to assess 178 autoworkers from 93 randomly selected pro duction jobs. Objective. To determine if five occupational LED risk evaluation methods yi elded similar assessments of manual material handling tasks. Summary of Background Data. Several techniques are available for quantifyin g LED risk in the workplace and are used in industry for job evaluation and redesign. It is unknown whether the methods yield similar results. Methods. The five job evaluation methods were the 1993 National institute f or Occupational Safety and Health model, the Static Strength Prediction Pro gram, the Lumbar Motion Monitor model, and two variations of the United Aut o Workers (UAW)-General Motors Ergonomic Risk Factor Checklist. These metho ds were selected because they represent common practice within the automoti ve industry, the result of governmental efforts to protect the workforce, o r models thought to be the most scientifically advanced. Results. Intercorrelations between methods ranged between 0.21 and 0.80. Pa irwise analysis of risk group classifications identified biases on the part of the National Institute for Occupational Safety and Health equation, whi ch considered jobs to be of higher risk relative to other methods, and on t he part of the Static Strength Prediction Program, which considered nearly all the jobs sampled to be low risk. Conclusions. There is little agreement among the five quantitative ergonomi c analysis methods used. In part, this may be because of their differential focus on acute Versus cumulative trauma, thereby suggesting that greater c onsideration needs to be given to the underlying causes of LED within a fac ility before selecting an ergonomic evaluation method.