Comparisons of physical exposure between workers harvesting apples on mobile orchard platforms and ladders, part 1: Back and upper arm postures. (November 2020)

• Record Type: Journal Article
• Authors: Thamsuwan, Ornwipa; Galvin, Kit; Tchong-French, Maria; Aulck, Lovenoor; Boyle, Linda Ng; Ching, Randal P.; McQuade, Kevin J.; Johnson, Peter W.
• Is Part Of: Applied ergonomics. Volume 89(2020)
• Publication Date: 2020-11
• Subjects: Human engineering -- Periodicals; 620.82
• DOI: 10.1016/j.apergo.2020.103193
• Languages: English
• ISSNs: 0003-6870

Abstract

Abstract: This study compared farmworkers' exposure to non-neutral postures using a new mobile platform apple harvesting method and the traditional method using ladders. Twenty-four workers were recruited and assigned into three groups: ladder workers ( n = 8) picking apples from full trees using a ladder, mobile platform workers ( n = 8) picking apples from upper part of the trees while standing on a moving platform, and ground-based mobile platform workers ( n = 8) picking apples from lower part of the trees which the mobile platform workers left out. Upper arm and back inclinations were continuously monitored during harvesting using tri-axial accelerometers over full work shifts (~8 h). Upper arm posture was characterized as the percentage of time that upper arm flexion and abduction exceeded 30°, 60°, and 90°. Back posture was characterized as the percentage of time that torso angles (sagittal flexion or lateral bending) exceeded 10°, 20°, and 30°. The 10th, 50th, and 90th postural percentiles were also calculated. The platform workers had lower exposures to upper arm flexion and abduction than the ground and ladder workers. There were no differences in torso angles between the ladder and mobile platform workers; however, the ground workers were exposed to more and greater percentages of time in torso flexions. Highlights: Upper arm and trunk postures of workers harvesting apples were measured using accelerometers. Compared to ladders, platforms can reduce postural exposures in the upper arms. By using platforms, workers harvesting apples only on the ground had the greatest back bending.