Ergonomic risk assessment of sea fishermen part V: muscle fatigue in Sardinian pot fishing

Abstract

We spent two full days aboard a ship to study muscle fatigue in Sardinian lobster fishermen. We investigated three tasks: 1) to drive the wheel, 2) to drop the pots, and 3) to sail the pots. For each task, we performed several surface electromyography (sEMG) acquisitions. After a 45 – 500 Hz band filter processing, we analyzed the signals at the beginning and at the end of the task. We recorded sEMG signals from the most involved muscles for each activity according to crew information. We analyzed the Median Power Frequency (MPF) values. Literature strictly correlated an 8% MPF reduction with muscle fatigue. In the first task, MPF of Right Deltoideus Lateralis after one hour of working time decreased from 79.7Hz to 73Hz. In the second task, there was a reduction of MPF after two hours of activity in three muscles. MPF of Left Deltoideus Anterior decreased from 66.7Hz to 59Hz, MPF of Left Deltoideus Anterior from 71.4Hz to 49.8Hz, and MPF of Left Trapezius Superior from 63.8Hz to 44.8Hz. Finally, in the third task, after three hours, we observed an MPF reduction in Right Deltoideus Lateralis (78.9Hz to 60.5Hz) and Right Trapezius Superior (from 56.2Hz to 38.9). Our results showed that in all the tasks, muscle fatigue occurs after less than half a working day. Muscle fatigue leads to an increased risk of developing musculoskeletal disorders in lobster fishermen.

Keywords: electromyography, fatigue, maritime workers

DOI: 10.54941/ahfe1005174