A mathematical modeling study is conducted to investigate neck coupling in helmeted head impacts. The main objective of the study is to provide direction for the experimental reconstruction of American football player impacts. Head responses are compared in MADYMO simulations of various impact scenarios without neck coupling, with an improved human neck model, and with a Hybrid-III neck model. The human neck model is a continued development of an existing neck model, with improved multi-directional biofidelity. Also the helmet model has substantial effect on the interpretation of the simulation results, and a model of an American football helmet is developed.

In the simulated impact scenarios, linear head accelerations show limited change as a result of neck coupling, but angular head accelerations change drastically depending on whether or not a neck is included in the model. Effects of body mass on head accelerations are limited for the impact conditions simulated in this study. This study shows that neck coupling should be accounted for if head linear and angular accelerations obtained from accident reconstructions are to be used to establish human tolerance.