The analysis of an individual difference in human skeletal alignment in seated posture and occupant behavior using HBMs

Izumiyama, Tomohiro<sup>1</sup>; Nishida, Norihiro<sup>2</sup>; Iwanaga, Hideyuki<sup>3</sup>; Chen, Xian<sup>4</sup>; Ohgi, Junji<sup>4</sup>; Mori, Koji<sup>4</sup>; Hayashi, Takafumi<sup>5</sup>; Sakuramoto, Itsuo<sup>6</sup>; Asahi, Ryusuke<sup>1</sup>; Sugimoto, Shigeru<sup>1</sup>; Ueno, Masaki<sup>1</sup>

Affiliations

¹Vehicle Development Div., Mazda Motor Corporation, Japan

²Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Japan

³Department of Radiological Technology, Yamaguchi University Hospital

⁴Department of Mechanical Engineering at Yamaguchi University

⁵Applied Medical Engineering Science, Graduate School of Medicine, Yamaguchi University

⁶Department of Mechanical and Electrical Engineering at National Institute of Technology, Tokuyama College, Japan

Abstract and keywords

To reduce fatalities or serious injuries, the object of this study was to research skeletal alignment in an automotive seat and clarify the differentiation by the factors of age, gender and body type. Additionally, it was also to create human body models which represent individual differences by morphing the skeletal alignment of THUMS based on the analysis results, and consider the structure of seats to ensure occupant safety by using those human body models. Analysis on X‐ray data revealed that the alignment in seated posture is classified into the following two types: mild S‐shaped and Kyphosis, and tends to be influenced by body mass index. To analyse the effects on occupant kinematics, especially the region of the abdomen and lumbar, by the difference of skeletal alignment in frontal impact, multiple models were created by morphing the skeletal alignment of THUMS ver.4. Then, the occupant kinematics has been studied by using those HBMs, and the results indicated a significant difference especially in pelvic region. Considering from the aspect of occupant protection in accidents, it shows that it is important to maintain the correct driving position.

Keywords: BMI; individual difference; seated posture; skeletal alignment; pelvis

Links

URL: http://www.ircobi.org/wordpress/downloads/irc18/pdf-files/84.pdf

Cited Works (3)

Year	Entry
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2016	Pramudita JA, Negishi J, Minato I, Nitsuma K, Mizoi K, Tamura N, Tanabe Y. Variation of spinal alignment in standing and automotive seated postures. In: Proceedings of the 2016 International IRCOBI Asia Conference on the Biomechanics of Injury. May 16-18, 2016; Seoul, South Korea.28-29.
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Cited By (10)

Year	Entry
2019	Draper D, Huf A, Wernicke P, Peldschus S. The influence of reclined seating positions on lumbar spine kinematics and loading in frontal impact scenarios. In: Proceedings of the 26th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 10-13, 2019; Eindhoven, Netherlands.
2019	Mizuno K, Hatano W, Yoshida R, Nakajima Y, Tanaka Y, Muroya T, Ishigaki R. The geometrical relationship between the lap belt and occupants' anterior superior iliac spine. In: Proceedings of the 26th International Technical Conference on the Enhanced Safety of Vehicles (ESV). June 10-13, 2019; Eindhoven, Netherlands.
2019	Izumiyama T, Nishida N, Iwanaga H, Chen X, Ohgi J, Asahi R, Sugimoto S, Fukushima M. Analysis of individual differences in pelvic shape and its impact on the seatbelt kinematics in a collision. In: Proceedings of the 2019 International IRCOBI Conference on the Biomechanics of Injury. September 11-13, 2019; Florence, Italy.44-46.
2020	Izumiyama T, Nishida N, Iwanaga H, Chen X, Ohgi J, Asahi R, Sugimoto S, Fukushima M. Identification of influential factors for seatbelt kinematics in a collision and analysis of their influence degree to the kinematics. In: Proceedings of the 2020 International IRCOBI Conference on the Biomechanics of Injury. 2020; Munich, Germany.456-469.
2021	Shibahara T, Nishimoto T, Motomura T, Matsumoto H, Asahi R, Sugimoto S, Fukushima M. Analysis of the effect of seated posture on vertebral compression fractures in frontal crashes using HBMs. In: Proceedings of the 2021 International IRCOBI Conference on the Biomechanics of Injury. September 8-10, 2021; Online.380-389.
2021	Pipkorn B, Östh J, Brynskog E, Larsson E, Rydqvist L, Iraeus J, Perez-Rapela D, Jakobsson L. Validation of the SAFER human body model kinematics in far-side impacts. In: Proceedings of the 2021 International IRCOBI Conference on the Biomechanics of Injury. September 8-10, 2021; Online.444-476.
2022	Leledakis A, Östh J, Iraeus J, Davidsson J, Jakobsson L. The influence of occupant’s size, shape and seat adjustment in frontal and side impacts. In: Proceedings of the 2022 International IRCOBI Conference on the Biomechanics of Injury. September 14-16, 2022; Porto, Portugal.549-584.
2022	Izumiyama T, Nishida N, Yamagata H, Asahi R, Chen X, Ohgi J, Sugimoto S, Fukushima M. Analysis of individual variabilities for lumbar and pelvic alignment in highly reclined seating postures and occupant kinematics in a collision. In: Proceedings of the 2022 International IRCOBI Conference on the Biomechanics of Injury. September 14-16, 2022; Porto, Portugal.941-955.
2023	Larsson E. Passenger Kinematics in Evasive Maneuvers: Advancing Active Human Body Modeling and Understanding Variability in Passenger Kinematics During Evasive Maneuvers [PhD thesis]. Götenburg, Sweden: Chalmers University of Technology; 2023.
2022	Draper D. Validation of Human Body Model Lumbar Spine Performance for Use in New Seating Positions [PhD thesis]. Ludwig Maximilian University of Munich; 2022.