Shoulder Muscles Activation during Oil Palm Fruit Harvesting Measured by Electromyography

The application of surface electromyography (sEMG) among oil palm fruit harvesters is still very few, despite subjective assessments that have identified the risk of musculoskeletal disorders (MSD), with the shoulder among the body parts with the risk. Thus, in this study, sEMG was used to measure deltoid and trapezius muscle activation while cutting fruit bunches. Because a prototype of the exoskeleton was also tested in this study, the muscle activation was compared without and with exoskeleton conditions. The field experiment was performed in a State-Owned Enterprise (SoE) plantation in West Java province, involving six experienced harvesters. A statistical analysis was performed to analyze the cutting cycle when harvesting. The results show that sEMG is capable of quantifying muscle activation when the subjects cut the fruit bunches. This may indicate that sEMG could become a very important instrument for investigating the risk of MSDs in the oil palm industry. Furthermore, the exoskeleton was found to be able to reduce muscle activation, especially toward the end of the experiment session. Future studies should consider the longer experiment session in a more controllable experimental setting to solidify the benefit of wearing an exoskeleton in oil palm fruit harvesting.