Effects of muddy terrain on lower extremity muscle activity and discomfort during the rice planting process

The agricultural industry in Thailand and many Southeast Asian countries relies heavily on manual labor with little utilization of advanced machinery. Prior investigation of the rice cultivation process indicated a high prevalence of musculoskeletal disorders and abnormal alignments in lower extremities (LEs) of Thai fanners. Since most tasks are typically performed with bare feet in heavy, muddy terrain, higher LE muscular force is required to compensate for mud viscosity. Consequently, this study investigated effects of muddy terrain on LEs of 30 experienced famers during simulated planting tasks of the rice cultivation process. Muscle activity and discomfort perception of LE joints were compared between rigid (No-Force) and muddy (Mud-Force) surface conditions, revealing significantly increased muscle activity and discomfort perception of knee and ankle in muddy work environments. The resulting high risk of knee and ankle injury for rice farmers should therefore be attenuated by development of appropriate protective equipment or assistive devices. Relevance to industry: The working surface constitutes a physical workplace environments with potential direct impact on productivity and safety of the workforce. In the agricultural industry, workers typically perform tasks on muddy terrain where, besides common slips, trips and falls, mud viscosity might intensify the force and lead to potential injury to the lower limbs.