Biomechanical Analysis on Vibration Characteristics of Lumbar Spine Using a Whole Human Body Finite Element Model

Most existing lumbar biomechanical studies relied on isolated lumbar spine models with simplified boundary conditions, which failed to fully capture the vibration transmission behavior and mechanical responses of the lumbar spine in an intact human body environment. The objective of this study was to establish a whole human body finite element model with detailed lumbar spine structures under a driving posture, and investigate the vibration characteristics of the lumbar spine in a whole-body physiological environment. Multiple validation tests were performed to ensure the accuracy of the model. The results of geometric measurement validation, static validation, and dynamic validation showed that the numerical values calculated by the proposed model were generally consistent with published data. Specifically, the first-order resonant frequency in the vertical direction obtained from this model was 5.2 Hz, which was closer to the 4-6 Hz range from in vivo experiments than the 11.7 Hz from the isolated lumbar spine model. The model established in this study had advantages over isolated lumbar spine models in terms of vibration transmission performance and could produce more accurate calculation results. It could provide a computational tool and a research basis for investigating lumbar injury mechanisms in drivers and conducting coupled mechanical analysis of the human body-seat system.