Analysis of Musculoskeletal Complaints and Work Posture Risks in the Rear Wheel Hub Plug Welding Process Using NBM REBA and RULA

Abstract

The plug welding activity on Wheel Hub Rear components in the welding division of PT SSC Works Surabaya is performed repetitively under working postures that may impose physical demands on operators. This study aimed to analyze musculoskeletal complaints using the Nordic Body Map (NBM), evaluate working posture risks using the Rapid Entire Body Assessment (REBA) and Rapid Upper Limb Assessment (RULA), and formulate ergonomic improvement recommendations. A descriptive case study approach was applied to seven plug welding operators. The NBM questionnaire was administered to all operators, while REBA and RULA assessments were conducted on Operator 1 based on the availability of adequate postural documentation. The NBM results showed that all operators experienced musculoskeletal complaints, with total scores ranging from 50 to 79. Two operators were classified as having a high level of complaints, while five were classified as moderate. The most prominent complaint was found in the right wrist, with a total score of 27, followed by the right upper arm, right lower arm, and right hand, each with a score of 25. The postural assessment of Operator 1 resulted in a REBA score of 11, indicating a very high risk requiring immediate action, and a RULA score of 7, indicating the need for immediate investigation and changes. Based on these findings, the proposed ergonomic improvements include an Adjustable foot platform, cable hanger, and active rest. The Adjustable foot platform is designed using D5 anthropometric data with an adjustable height mechanism to help reduce the need for trunk flexion during the welding process.