Graduation Year


Document Type




Degree Granting Department

Environmental and Occupational Health

Major Professor

Stuart M. Brooks, M.D.

Committee Member

Thomas Truncale, D.O.

Committee Member

Thomas E. Bernard, Ph.D.


first time occupational visit, distal upper extremity, Strain Index, case job, sensitivity, specificity


Work-related musculoskeletal disorders (MSDs) account for more than 350,000 occupational illnesses and injuries in the United States. Many job risk factors for developing MSDs are found in the automotive industry and the United Automobile Workers (UAW)-Ford Ergonomics Surveillance Tool (EST) has been designed to screen these jobs into high, moderate or low risk for work-related musculoskeletal disorders affecting the distal upper extremity (DUE), lower back (LB) and/or neck and shoulders (NS). The purpose of this effort was to examine the predictive validity of the EST against a sample of target jobs at four Ford plants.

Individual jobs for this study were selected by a stratified random assignment. Health records from Ford were reviewed in order to identify first time office visits (FTOVs), which were symptomatic complaints made by individual workers. Jobs that were associated with FTOVs were defined as case jobs for the three body regions. These case jobs were compared with predictions for injury by EST. Sensitivity and specificity were used to test predictive validity.

While the sensitivity was poor for all body regions tested, the specificities were fairly strong for DUE and NS when looking at low risk compared to moderate/high risk. The low risk DUE specificity was 0.67 and increased to 0.78 when looking at low/moderate risk compared to high. Low back specificity for low risk was 0.51 but increased to 0.85 when looking at low/moderate risk compared to high. The NS specificity score was 0.81, increasing to 0.85 when looking at low/moderate risk. While the EST does not predict which jobs are high risk for injury, it does screen out safe jobs. Therefore, jobs identified by the EST as low/moderate risk are likely to be safe.