An application of Monte-Carlo simulation to RULA and REBA

Abstract

The use of ergonomic evaluation tools can help in identifying the potential for musculoskeletal disorders (MSDs) arising from the design of work tasks. Rapid upper limb assessment (RULA) and rapid entire body assessment (REBA) are ergonomic assessment tools developed to evaluate the risks associated with these disorders. Both tools primarily evaluate these risks by examining body joint angle inputs, specifically by estimating a single joint angle, but in realistic situations, a full range of angles experienced is required to produce reliable evaluation. Furthermore, users of these tools may be uncertain of his/her estimation, especially if only a single joint angle is considered. A new approach based on Monte-Carlo simulation (MCS) in which joint angles are represented in distributions instead of single values is proposed to handle such issues. An empirical example is presented to compare traditional RULA and REBA to Monte-Carlo-RULA/Monte-Carlo-REBA approaches. The proposed approach exhibited a higher degree of sensitivity with respect to joint angles associated with variability and uncertainty.