Analysis of Working Postures in a Small-Scale Fastener Industry by Rapid Upper Limb Assessment (RULA) Using CATIA Software

Abstract

Digital Human Modeling (DHM) has emerged as an important tool in the simulation of workplaces to provide better solutions for ergonomic and workstation design. Digital human manikins are incorporated into software, which can be easily manipulated to assess workstation design, discomfort and related injuries leading to development of musculoskeletal disorders. Workers in small-scale industries often complain about pain and discomfort while carrying out the tasks. If not addressed at the initial stages, this may lead to further development of work-related musculoskeletal disorder and other serious issues like Low Back Pain (LBP), affecting the workers’ efficiency and productivity. The objective of study is to analyze the work postures in small-scale fastener industry by Rapid Upper Limb Assessment (RULA) tool in CATIA software. The process consists of cold forging of bolts on header machine, trimming, threading and heat treatment. The operators’ work postures are assessed using RULA and then the actual postures are reconstructed in CATIA software to find out level of risk. The postures are again reconstructed to show possible improvements using ergonomics intervention. For example, a posture of operator at cold forging machine was assessed by RULA and a score of 7 was obtained, meaning high risk. After applying ergonomics intervention and redesign of workstation in CATIA, the improved posture resulted in a final RULA score of 4, indicating medium risk. Some of the worst postures are analyzed and improvements are suggested based on anthropometry and ergonomic principles. The results show poor working posture risk can be reduced effectively by using ergonomic interventions.