STUDY DESIGN: Strength testing of lumbar extensors of shipyard workers without back injury claims was accomplished to compare isolated lumbar strength with the severity of their workplace physical demands and the incidence of workplace back injury during a 2-year period. OBJECTIVES: To determine if strength is a predictor of workplace injury and if there is a relationship between the physical demands of the job and strength. SUMMARY OF BACKGROUND DATA: The role of preplacement strength testing has not been clarified as a potential means for predicting workplace injury. It has not been clarified whether work activity affects the strength of the worker. METHODS: One hundred fifty-two shipyard workers were strength tested for isometric lumbar extensor strength. They had been classified as to the severity of their job demands according to the Physical Demand Characteristics. All workers at this industry were likewise classified. Those workers who were tested were followed for 2 years to evaluate for claims of back injury. RESULTS: There was a higher incidence of low back injuries in the heavy and very heavy classification. There was, however, no difference in strength among those workers classified in medium, heavy, and very heavy work. Nine percent of those workers tested had back pains during the following 2 years. All but two had higher-than-average strength. CONCLUSIONS: There is no evidence that preplacement back strength testing would predict workplace claims of injury.
STUDY DESIGN: Strength testing of lumbar extensors of shipyard workers without back injury claims was accomplished to compare isolated lumbar strength with the severity of their workplace physical demands and the incidence of workplace back injury during a 2-year period. OBJECTIVES: To determine if strength is a predictor of workplace injury and if there is a relationship between the physical demands of the job and strength. SUMMARY OF BACKGROUND DATA: The role of preplacement strength testing has not been clarified as a potential means for predicting workplace injury. It has not been clarified whether work activity affects the strength of the worker. METHODS: One hundred fifty-two shipyard workers were strength tested for isometric lumbar extensor strength. They had been classified as to the severity of their job demands according to the Physical Demand Characteristics. All workers at this industry were likewise classified. Those workers who were tested were followed for 2 years to evaluate for claims of back injury. RESULTS: There was a higher incidence of low back injuries in the heavy and very heavy classification. There was, however, no difference in strength among those workers classified in medium, heavy, and very heavy work. Nine percent of those workers tested had back pains during the following 2 years. All but two had higher-than-average strength. CONCLUSIONS: There is no evidence that preplacement back strength testing would predict workplace claims of injury.