The effects of the muddy surface environment on heart rate and pain perception in the lower extremity during the paddy planting activity

The agricultural industry of many Southeast Asian countries, including Indonesia, is highly reliant on human labor, with minimal use of modern equipment. Preliminary studies on the paddy planting activity revealed a significant occurrence of musculoskeletal disorders (MSDs) and structure malalignments in the lower extremities. This is because these farmers usually execute paddy planting activities on heavy and muddy terrain with bare feet using more significant lower extremity muscle. The exhaustive activity of muscles leads to an increase in the heart rate response as the muscle demand for energy is higher. This condition causes a decline in muscle performance. Therefore, this research examines the effect of muddy terrain on the lower extremity of 30 experienced rice farmers through simulated rice planting activities in terms of heart rate response and perceived pain. The Suunto wristband and the modified Standardized Nordic Questionnaire (SNQ)-visual analog scales (VAS) for perceived pain questionnaire were used to collect the data of heart rate response and pain perception on the lower extremity, which were compared between muddy (mud force) and flat rigid (no mud force) terrain, respectively. The Repeated Measure ANOVA test revealed that muddy work terrain had a significant effect on heart rate (100.11 ± 1.71 beat per minute) compared to flat rigid terrain (94.13 ± 1.16 beat per minute). Meanwhile, the paired T-test results showed that muddy work terrain had a significant effect on the increase in pain in the farmer's lower extremity when performing rice planting activities compared to flat hard terrain. The results of this study can be used for modifying the work-break interval arrange and as a basis for the development of an assistive device capable of preventing injuries to the lower extremity caused by muddy work surface conditions.