Comparing Upper Arm and Back Postural Exposures between Apple Harvesting with Ladders and Mobile Platform

Abstract

In the US tree fruit industry, in attempt to improve the efficiency of orchard workers; harvest-assisting mobile platforms have been introduced. However, the effect these mobile platforms have on physical exposures, i.e. non-neutral work postures, has not been evaluated. The purposes of this study were to compare ergonomic risk factors between a new apple harvesting method using mobile platforms and the traditional method using ladders. Twenty-four workers participated in this study and were equally divided into three groups, harvesting apples from ladders (n = 8), mobile platforms (n = 8) and the ground (n = 8). Upper arm and back inclinations were continuously monitored and calculated over the whole work period, excluding breaks. Upper arm posture was characterized in terms of the percent of time when upper arm flexion and abduction exceeded 30, 40, 50, 60, 70 80 and 90 degrees. Back inclination was characterized as the percent time forward bending exceeded 10, 20 and 30 degrees. The results showed that the workers on the mobile platform typically had lower postural exposures than the ground and the ladder workers, respectively.

An evaluation of wearable sensors and their placements for analyzing construction worker's trunk posture in laboratory conditions

“…The participant concurrently wore multiple AGs. Several studies (Driel et al, 2013;Graham et al, 2009;Schall et al, 2015;Thamsuwan and Johnson, 2015;Veltink et al, 1996) have attached accelerometer sensors to the anterior torso between the sternum and the sternal notch for trunk flexion and lateral bending angle measurement. Therefore, the current study selected this location of the anterior torso (hereinafter referred to as "chest") as the reference placement for the upper body trunk flexion.…”

“…Bernmark et al (2011) evaluated a tri-axial accelerometer as a tool to analyze the head movement inclination in computer work tasks. Thamsuwan and Johnson (2015) used tri-axial accelerometers for evaluating non-neutral work postures of the upper arms and back required by orchard workers' apple harvesting activities. Dahlqvist et al (2016) validated a low-cost tri-axial accelerometer for measuring the inclination angles and velocities of the head, upper back, and upper arm movements with painting, computer work, furniture polishing, and elevated arm activities.…”

“…Whereas the wearable attachment method of the ZB was intended for sports activity and occupational researches, the pouch and belt system of the AG were designed for the general population. For occupational research and the practical implications of the AG system for trunk posture measurement, a secured and wearable attachment should be designed for the construction industry which requires active trunk movement, as Thamsuwan and Johnson (2015) designed and applied in their research.…”

Critical Ergonomics and (Dis)Comfort Factors While Performing Tasks with Hand Tools on a Ladder: A Pilot Study

“…The most investigated factors regard heavy loads and manipulation of objects while working at heights; incongruous posture, and repetitive arm use; loading/unloading ladders from vehicles; and placing ladders on the shoulder to move them. Some studies have been conducted, especially in the agricultural sector, and during apple harvesting operations [25][26][27][28][29]. In [25,26], two different apple harvesting methods were compared: a conventional ladder and a newly developed mobile platform.…”

“…Some studies have been conducted, especially in the agricultural sector, and during apple harvesting operations [25][26][27][28][29]. In [25,26], two different apple harvesting methods were compared: a conventional ladder and a newly developed mobile platform. In [28,29], the analysis carried out using the RULA [30] method is aimed at identifying uncomfortable postures/activities that occurred during apple harvesting.…”