Wearable Sensor-Based Assessment of Occupational Workload During Coastal Gillnet Fishing: An Exploratory Field Study

Assessing occupational workload under dynamically unstable offshore conditions is challenging because physiological demands and biomechanical exposures may vary across tasks and may not be adequately characterized using a single measure. This exploratory field study characterized physiological, ergonomic, and kinematic workload during coastal gillnet fishing using an integrated assessment approach. Four fishermen (one captain and three crew members) were monitored during three fishing sessions under real offshore conditions. Heart rate, physical activity, ergonomic exposure using the Quick Exposure Check, and lumbar–pelvic kinematics using inertial measurement units were assessed across operational phases. Workload was temporally concentrated during hauling, with heart rate and physical activity increasing particularly during the mid-to-late hauling stages. Ergonomic exposure of the lower back, shoulder/arm, and neck also increased during hauling. Kinematic analysis revealed moderate trunk flexion accompanied by non-neutral flexion exposure of up to 28.62%, while the lumbar contribution to lumbar–pelvic motion frequently exceeded 50%. These findings suggest that integrating wearable sensing with ergonomic assessment may help characterize task-specific workload patterns that are not readily captured by average physiological intensity alone. This approach may support field-based occupational workload assessment in dynamically unstable working environments.