Motion and postural risk analysis for agricultural soil pivot type trailer hitching system on two-wheel tractor

The operation of a conventional trailer on a two-wheeled tractor shows that it is ergonomically risky, especially during turns, where the Rapid Upper Limbs Assessment (RULA) analysis shows a very high level of risk, namely the level of action 4, which requires immediate investigation and repair because it can cause injury to the operator. Modifications that have been made are the design of the pivot-type trailer towing system on two wheels that can improve operator comfort. This study aims to analyse the motion and posture of the operator in the operation of a pivot-type trailer on a two-wheeled tractor using the RULA method. The sample consisted of 4 operators representing the 5th, 50th and 95th percentiles of Indonesians, the operator video recording data when operating the tractor and trailer with various track conditions, loads, speed, straight motion or turns were collected. Analysis of the operators was carried out quantitatively, namely the RULA method. The results of the RULA analysis show that in the operation of the pivot-type trailer hitching system, it has a score of 3 for straight motion and a score of 4 for turning movements, so the level of action required is 2 which means further investigation is needed. The RULA analysis shows that the pivot-type trailer hitching system has succeeded in improving the RULA score compared to conventional trailers so as to reduce the risk of musculoskeletal disorder (MSD) to the operator.