Effect of Changing Task Sequence on Physical Workload in Agricultural Operations

Abstract

To improve work efficiency and reduce the risk of injury in agriculture, this study focused on altering the task sequence to reduce physical workload. Based on typical agricultural activities, three types of tasks were designed to involve different body parts and movement characteristics (lifting heavy objects, repetitive light work in a forward-bending posture, and holding heavy objects with one hand). The impact of different task sequences on physical movements was evaluated using the joint angles and center of pressure (COP) displacement measured during the lifting task. Body movement data were collected from 12 healthy participants (23.1±1.3 years old) using a motion capture system and force plates across six experimental protocols with different task sequences. The statistical analyses of the knee joint angle, hip joint angle, and COP displacement revealed no significant differences among the six protocols. The mean knee joint angle was approximately 100°, with a relatively high interparticipant variability. The hip joint angles ranged from approximately 138° to 144°, with slightly lower mean values observed when the protocol began with holding a heavy object with one hand. The average COP displacement was approximately 34 mm across all the protocols, although a slightly greater interparticipant variability was observed when repetitive forward-bending movements were performed in the initial phase. These results suggest that the joint angles and COP displacement obtained from a representative task may be useful indicators for evaluating the physical workload in multitask agricultural operations.

Keywords: Task Sequence, Physical Workload, Agriculture, Motion Capture, Force Plate

DOI: 10.54941/ahfe1007336