Comparing the results of eight methods used to evaluate risk factors associated with musculoskeletal disorders

Abstract

This paper presents a comparison between eight different methods for determining risk factors for work-related musculoskeletal disorders. The Quick Exposure Check (QEC), the Ergonomic Workplace Analysis developed by the Finnish Institute of Occupational Health (FIOH), ACGIH's Hand Activity Level threshold limit values method (HAL), the Job Strain Index (JSI), the OCRA index, the EN 1005-3 standard, the Rapid Upper Limb Assessment (RULA) and the Rapid Entire Body Assessment (REBA) methods were all used to assess 224 workstations involving 567 tasks in various industrial sectors. The results are compared using three risk categories (low, moderate, high). Data were gathered using video and measurements taken at the workstations. A questionnaire was also administered to employees participating in the study. The findings reveal that the various methods differ in their analyses of the same workstation. The EN 1005-3 standard assessing risk to the shoulder was the most conservative, identifying over 86% of the workstations as high risk. The HAL classified 37% of the workstations as low-risk to the hand and wrist compare to JSI with 9%. Correlation was highest between RULA and REBA, and between JSI and HAL. The FIOH, RULA and REBA methods did not identify any workstations as low risk. The QEC method proved to be the less stringent in assessing overall risk, classifying 35% of the workstations as high risk compare to RULA with 76%. The QEC Hand/wrist and OCRA Hand/wrist/elbow indices showed similar results for the number of workstations classified as high risk, but did not classify the same workstations in this category. OCRA and QEC were in agreement 57% of the time for all risk categories combined. Relevance to industryThese results provide a better understanding of the differences between various risk assessment methods. This information should be particularly useful for practitioners when choosing a method prior to an ergonomic intervention in industry.