Assessment of Driving Posture Ergonomics in LPDT Operators using the Rapid Upper Limb Assessment Method

This study aimed to determine the postural risk of Low-Profile Dump Truck (LPDT) operators working in an underground metal mine. A total of 38 LPDT operators aged between 18 and 56 years, with at least 6 months of professional driving experience and no history of injuries, were selected for this study. The postural data of operators were collected by placing the Nikon D5600 camera inside the 20-ton capacity LPDT cabins which are equipped with various ergonomic features such as gas seat suspension, adjustable seat height and backrest. The driving postures of operators were recorded in the sagittal plane while performing various job cycles such as loading, loaded travel, unloading and empty travel. The ergonomic assessment of these postures was done using the standard Rapid Upper Limb Assessment (RULA) chart. The results of this analysis showed that LPDT operators were sitting in the driving posture corresponding to the low (86%) and medium (14%) risk of Work-Related Musculoskeletal Disorders (MSDs). Further, it was observed that the mean RULA score during the dynamic operations (i.e. loaded and empty travel) was relatively high compared to the static operation (i.e. loading and unloading). The visual examination of the video footage showed that the operators faced visibility issues and were compelled to lean forward to see the road clearly. This resulted in a high RULA score during dynamic operation. The study highlighted the need for ergonomic intervention to prevent the LPDT operators from MSDs.