Muscle fatigue assessment using surface electromyography in farm operations performed in protected cultivation

The agricultural operations such as digging, transplanting and weeding in protected cultivation are performed by both female and male workers. The posture adopted during these operations such as forward bending and squatting leads to the involvement of various muscle groups and leads to continuous exertion. Excessive loading and long working hours result in work related musculoskeletal disorders. Surface electromyography (sEMG) is a useful tool to measure and correlate muscle fatigue experienced by workers during these operations. In the present study,twelve workers (six female and six male) performed digging, transplanting and weeding operations using both traditional and improved tools inside a polyhouse (560 m²). The muscles selected for digging and transplanting operations were the brachioradialis (BR), biceps brachii (BB), triceps brachii (TB), anterior deltoid (AD), erector spinae longissimus (ESL) and biceps femoris (BF). For weeding, all the muscles remain the same except for the biceps femoris, which is replaced by the gastrocnemius (GC). Before the start of the experiments, the worker's maximum voluntary contraction (MVC) values were assessed using information gathered from reviews. For female workers, with traditional tools, the percentage of muscle fatigue for the digging was (bicep femoris-58.19%, erector spinae- longissimus-53.79%, biceps brachii-31.48%), weeding was (brachioradialis-33.59%, gastrocnemius -33.35%) and transplanting was (bicep femoris-37.53%), respectively. Similarly, male workers, with traditional tools, the percentage of fatigue for the digging (bicep femoris-50.50%, erector spinae- longissimus (ESL)-49.99%, biceps brachii-31.55%), weeding (brachioradialis-28.83%, gastrocnemius-28.70%) and transplanting (bicep femoris-31.62%), respectively. Using the improved tools and machinery mini power tiller (BF:80.24%-F, 85.42%-M, ESL:75.35%-F, 79.93%-M, BB:33.83%-F, 37.50%-M), cycle hoe weeder (ESL:83.06%-F, 86.73%-M, GC:76.00%-F, 85.27%-M, BB:55.65%-F, 61.90%-M), single row vegetable transplanter (BF:90.43%-F, 93.51%-M, ESL:77.39%-F, 82.22%-M, BB:23.48%-F, 27.27%-M) results in decreased muscular load as compared to traditional tools/machinery. The data suggests that the use of improved tool and machinery can help to reduce muscle fatigue and enhance the safety and productivity of workers.