Global Journal of Researches in Engineering, G: Industrial Engineering, Volume 23 Issue 2

approximately 14kg. However, the actual weight of the door ranges from 120kg to 500kg[27]. Therefore, the applied hand force needed to open the door could be much larger than the 140N used in Task#1. At pose#2, the average A/P shear was 691.2N when the exerted hand force was 140N, which is very close to the recommended safety threshold value of 700N [28]. This suggests that there is a high likelihood of injury to aircraft attendants when opening real passenger doors with larger weights. Thus, the design of the door hinge is a critical factor in preventing injury to aircraft attendants. In Task#2, which involved lifting the luggage from the floor and placing it into the overhead compartment, most of the variables exhibited significant differences between two specific poses, except for the right/left shoulder abduction/adduction. This may be due to the constraints of the two grabbing points on the luggage. The angles of trunk and hip flexion were identified as factors that led to a significant difference in spinal forces exerted on the lower back [24,26]. At Pose#1 in Task#2, the male participants exerted approximately 30% higher spinal forces than the females. From the cross-correlation analysis, it was observed that trunk flexion was correlated to the spinal forces, including compressive and A/P shear forces, with R values of 0.64 and 0.50, respectively. It appeared that while lifting the luggage from the floor, males flexed their trunks more than females, with both genders having a large hip flexion. This could be attributed to body height differences, as the 15cm gap in height made it easier for male participants to flex their trunks and reach the luggage [26]. The statistical analysis supported this conclusion, as evidenced by the R values of 0.86 and 0.72 for the correlation between body height and spinal forces. Although the amplitude of spinal forces decreased at Pose#2, there was still a significant difference in compressive force exerted on the lower back between genders. The correlation between trunk movement and spinal forces remained relatively high, with R values of 0.71 and 0.43. To complete the task, subjects had to extend their trunk to put the luggage into the overhead compartment. Trunk extension is beneficial in reducing the risk of lower back injury during the lifting task [29,30]. Due to their relatively shorter body height, female participants had to reach further and extend their trunks more than male participants to place the luggage, resulting in less compressive spinal force being exerted on them. As participants placed the luggage into the compartment, they adopted a nearly neutral pose, which caused the weight of their upper body and the objects to be supported by their lower back. Consequently, the magnitude of compressive force at this specific pose showed a moderate correlation with the variable body weight, with an R value of 0.53. In Task#2, the maximum hand force was predicted to occur when the load exerted on the lower back was greater than the recommended safety threshold for the either compressive force of 3400N [31] or the safety threshold for the shear force of 700N [28]. Our results indicated that this might cause a high risk of injury for aircraft attendants if the predicted force exerted by each hand reached 48N. In this case, the weight of the luggage should not exceed 10kg. However, airlines have different requirements for carry-on luggage, and the weight ranges from 7kg to 15.75kg [20]. To prevent injuries to aircraft attendants, the weight of carry-on luggage should be limited. V. C onclusion We have successfully assessed the risk of injury to aircraft attendants during their routine tasks by identifying key factors that could lead to injuries, such as objects with heavy weight, and postures adopted by attendants that may affect the spinal load exerted by the lower back. To reduce the risk of injury, it is crucial to reduce the weight of objects and to minimize upper body flexion for aircraft attendants, especially when assisting passengers in lifting luggage into the overhead compartment. Our study provides an opportunity for airline companies to monitor the injury risk of aircraft attendants and develop safety training programs based on real-time ergonomic results. Furthermore, this innovative fusion technology can be applied to other occupational fields, such as underground mining and manufacturing assembly lines, to prevent injuries and ensure worker safety. R eferences R éférences R eferencias 1. U.S. Bureau of Labor Statistics. Nonfatal workplace injuries and illnesses for flight attendants in 2019: The Economics Daily: U.S. Bureau of Labor Statistics. Available online: https://www.bls.gov/opu b/ted/2021/nonfatal-workplace-injuries-andillnesses- for-flight-attendants-in-2019.htm (accessed on July 14, 2022). 2. Pasternack Tilker Ziegler Walsh Stanton & Romano LLP Attorneys At Law. Flight Attendant Injury Claims. Available online: https://www.workerslaw.com/flight- attendant-workers-comp-claim/ (accessed on March 18, 2022). 3. Lombardo, K. DORN. Airline and Air Freight Workers Face High Injury Risks-Here’s How to Keep Them Safe. Available online: https://www.dorncompanies. com/airline-and-air-freight-workers-face-high-injury- risks-heres-how-to-keep-them-safe/ (accessed on June 21, 2022). 4. Smagacz, J. Industrial and Systems Engineering at Work. Ergonomic enhancements improve safety for airline cabin crews. Available online: https://www. Global Journal of Researches in Engineering Volume XxXIII Issue II Version I 10 Year 2023 © 2023 Global Journals ( ) G Evaluating the Risk of Injury for Aircraft Attendants using Virtual Reality and Advanced Motion Tracking System Integrated with Ergonomics Analysis