Investigation of Conditions that Affect Neck Compression- Flexion Injuries Using Numerical Techniques.

A Finite Element (FE) model of isolated head and neck complex was developed aiming to investigate the mechanisms of injury from axial impacts, in the sagittal plane, and the injury thresholds from experimental studies reported in the literature. The model was validated on a local and a global level, showing a significant correlation with experimental investigations and thereby having the potential to predict both reported injuries and dynamic buckling modes. The frequently reported Hangmans' fracture was predicted to occur at an axial load of about 3.5 kN and at a local injury threshold of 191 MPa in the compact bone of C2. Also, when analyzing an experimentally designed inner roof of a vehicle, the FE model showed that an induced anterior translation of the head reduced both stress and forces of the cervical spine bone. Moreover, the recent FE model suggests that combined compression/flexion may result in less severe injuries compared to pure compression or compression extension.