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. 2025 Aug;53(8):1931-1943.
doi: 10.1007/s10439-025-03745-8. Epub 2025 May 15.

Importance of Neck Boundary Condition and Posture on Cervical Spine Response Assessed using a Detailed Finite Element Human Model in a Head-First Impact

M I Morgan  1 , M A Corrales  1 , H Kaur  1 , P A Cripton  2 , D S Cronin  3
Affiliations

Importance of Neck Boundary Condition and Posture on Cervical Spine Response Assessed using a Detailed Finite Element Human Model in a Head-First Impact

M I Morgan et al. Ann Biomed Eng. 2025 Aug.

Abstract

Purpose: Head-first impacts (HFI) are associated with a high risk of cervical spine trauma. Experimentally, HFI use an inverted full body (FB), or a head and neck with torso surrogate mass (TSM) attached to the first thoracic vertebra. FB testing is complex and few studies have been completed, while more testing has been done in the TSM configuration, no comparison of the two setups exists.

Methods: In this study, the effect of TSM and FB on the head and neck response was investigated computationally using three initial neck postures (flexed, neutral, and extended). The TSM was applied to an extracted head and neck from a contemporary full body model, while the FB was used for comparison. The models were inverted and dropped on a rigid plate at three velocities (2.0, 3.1, and 3.6 m/s). Head impact force, head and neck kinetics, vertebral kinematics, and internal energy were measured and compared between the models.

Results: TSM models demonstrated higher neck forces, and internal energy, compared to FB models. Despite similar head contact forces, the compliant thorax of the FB model reduced the neck forces and energy. The neutral and extended posture predicted higher neck forces due to facet joints engaging, while anterior head translation in the flexed posture reduced neck forces.

Conclusions: This study identified that the neck response using a TSM boundary condition differs from a FB condition, leading to higher neck loads, and that lordotic neck postures lead to higher neck forces compared to a kyphotic initial posture.

Keywords: Cervical spine response; Full body; Head-first impact; Human body model; Posture effect; Torso surrogate mass.

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Conflict of interest statement

Declarations. Conflict of interest: The authors have no conflict of interest to declare.

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References

    1. Viano, D. C., C. S. Parenteau, M. M. Gopal, and M. B. James. Vehicle and occupant responses in a friction trip rollover test. SAE Int J Passeng Cars—Mech Syst. 2(1):942–960, 2009.
    1. Al-Salehi, L., S. G. Kroeker, J. R. Kerrigan, P. A. Cripton, M. B. Panzer, and G. P. Siegmund. Cervical vertebral and spinal cord injuries in rollover occupants. Inj Epidemiol. 11(1):30, 2024. - PubMed - PMC
    1. McElhaney, J., R. Snyder, J. States, and M. Gabrielsen. Biomechanical Analysis of Swimming Pool Neck Injuries. In the Automotive Engineering Congress and Exposition. SAE Tech. Pap. 790137, 1979.
    1. Torg, J., J. Vegso, M. O’Neill, and B. Sennett. The epidemiologic, pathologic, biomechanical, and cinematographic analysis of football-induced cervical spine trauma. AJSM. 18(1):50–57, 1990.
    1. Yoganandan, N., F. A. Pintar, M. Haffner, D. J. Malman, H. Nichols, J. Jentzen, S. S. Weinshel, S. J. Larson, and A. Sances Jr. Epidemiology and Injury Biomechanics of Motor Vehicle Related Trauma to the Human Spine. SAE Tech. Pap. 892438, 1989. https://doi.org/10.4271/892438

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