This study outlines the development and validation of a detailed finite element model of a 50th percentile male cervical spine. This work is part of a larger collaborative effort to produce a full human body model for the automotive community. The goal of this work is to produce a detailed, biofidelic and frangible human body model that will provide a valuable tool in automotive safety research.

The geometry of the vertebrae and muscle tissue in the model were derived from CT scans of a volunteer and the cervical vertebrae were positioned according to available literature for intervertebral disc spacing, the relative positions of vertebral landmarks, and spinal curvature reported for a seated 18-24 year old male. All of the relevant tissues were incorporated in the model, including the vertebrae (cancellous and cortical bone), the discs with representations of the annulus fibrosus, ground substance and nucleus pulposus, the facet joints, and the ligaments. The muscle in the model included 3D solid elements to represent the passive tissue properties, with embedded axial elements using a Hill relationship for the active properties. All of the material properties in the model were derived from the literature, while the ligament properties were measured experimentally at deformation rates relevant to automotive crash scenarios.

The model was validated using a hierarchical approach, beginning at the segment level with physiological loads. Subsequently the full spine was validated using 15g frontal, 7g lateral, and 4g rear impacts. The model was found to generally agree with the cadaver studies at the segment level and the volunteer studies at the full spine level without calibration of the material properties to improve the model response.