The effect of football helmet energy absorption mechanisms on the mitigation of cervical spinal injuries: a mathematical model

Abstract

A model was developed to examine the effect of different football helmet designs on energy dissipation and injury mitigation during head-on impacts which approach, but do not exceed, critical cervical spinal cord injury threshold levels. Based upon the simulations, increasing in neck damping provides for significant reductions in peak cervical spinal loads. Helmet damping has a negligible effect on air cell helmet performance, but has a significant, deleterious impact on padded cell helmet performance. Moreover, cervical spinal loads are highly sensitive to player weight distribution and player initial velocity since these variables determine the amount of initial kinetic energy which must be absorbed by the helmet, head and neck system. Finally, a novel football helmet energy absorption curve has been developed which limits cervical spinal loads to approximately 800 lbf. through barometrically-controlled pressure relief valves up to player initial velocities of 30 ft/sec. Conclusions based primarily upon the results of the velocity and helmet damping analyses show that different football helmet energy absorption mechanisms can make a substantial, quantifiable difference in cervical spinal loads during low to moderate player velocity impacts at threshold energy levels.