Musculoskeletal Disorder (MSDs) and Rapid Upper Limb Assessment (RULA) Scoring Among Rubber Tappers

Due to a large population at risk of MSDs in the rubber tapping occupation, this study aimed to survey the MSD problems on different parts of rubber tappers' bodies, and evaluate the RULA scoring system in terms of its pain prediction ability. 427 rubber tappers actively engaged in rubber tapping for at least 1 month, aged between 15-60 years, were recruited. Data were gathered using a questionnaire-based interview with an analog pain rating scale and a body discomfort chart. Video-based analysis of the various most common rubber tapping postures using the RULA method was also done. Factor analysis was used to group the correlated items of the RULA body part scores and pain scores from the relevant regions. Linear modeling was also performed to determine the ability of the various RULA factors to predict the associated pain scores. 52.9% of the rubber tappers reported current back pain, while pain at other bodily areas was uncommon (2.1%-14.8%). In contrast, the RULA scores did not indicate the back to have the highest risk. Factor analysis found the RULA scores could be grouped into 3 factors. Linear modeling demonstrated a significant association between back pain and the RULA factor involving the vertebra and upper arm. However, the RULA scores had a poor predictive ability concerning body pains of the rubber tappers (R-squared=0.08), and further studies on the causes of back pain are needed.