Verification of Lower Neck Shear Force as a Rear Impact Injury Criterion

Shear force remains a viable candidate for a lower neck rear impact injury criterion. At the 2007 IRCOBI meeting, data were presented demonstrating a correlation between lower neck shear force and cervical facet joint motions. The present study consisted of three parts. A review of automotive literature correlated lower neck shear force to experimentally-induced injuries in PMHS and demonstrated sensitivity of the metric to changes in test conditions. An experimental test series demonstrated greater sensitivity of lower neck shear force to impact velocity and seatback orientation than existing injury criteria. Finally, a comprehensively validated computational model correlated test conditions resulting in greater lower neck shear force magnitudes to increased facet joint ligament strains. The present study provided continued evidence for the advancement of lower neck shear force as an automotive rear impact injury criterion.