Auto-Mechanics' Mental Workload and Posture Risk Assessment in Automobile Repair Shop: A Case Study

This study assessed the auto-mechanics' four dimensions of mental workload and posture in an automobile repair shop in San Jose Occidental Mindoro, Philippines, with issues in increasing body pains and headaches affecting efficiency and performance. Five participants were observed from January-March 2022. Due to the limitations of the NASA-TLX in evaluating the mental workload, the authors used the new Carmen-Q questionnaire. Results revealed that the auto-mechanics had been exposed to an average of twenty-nine (29) in the cognitive dimension, eighteen point five (18.5) in the temporal dimension, seventeen point five (17.5) in the emotional dimension, and seventeen points seventy-five (17.75) in performance dimension, which means that the auto-mechanic's mental workload is in the medium range and preventive measures must be done. Previous research also revealed that mental workload is linked with poorer posture; thus, this study is the first to combine mental workload with posture risk assessment. RULA and REBA techniques have been utilized to evaluate the posture, and results discovered that the risk index for tire repair and installation is two (2.00) and three (3.0) for the engine repair and installation, which means that the risk is high and change in posture is required. Statistical analysis also described that the cognitive and emotional dimension has a significant relationship with each other. In contrast, the different dimensions have no significant relationship, such as: cognitive and temporal dimensions, cognitive and performance dimensions, temporal and emotional dimensions, temporal and performance dimensions, and emotional and performance dimensions. In conclusion, this study can be considered a basis for helping the automobile repair shop design the tasks for the auto-mechanics as well as guidance in improving the working conditions and a tool for evaluating cognitive state in a critical working environment.