Evaluation of Head Linear and Rotational Acceleration Response to Various Linear-Induced Impact Scenarios

Incidents resulting in head injury generally involve components of both linear and rotational motion. The protection of the head from injury most often comes from the use of some form of helmet. Helmets currently are designed only to protect the head from linear accelerations. Recent research involving the analysis of concussion in professional football suggested that linear accelerations are more consistent in the prediction of concussion, with the resultant rotational accelerations correlating to the peak linear accelerations of the impact.

This research proposes to determine if the situation of the head impact has an effect on the correlation of the linear and rotational accelerations, as well as to determine if the linear acceleration is consistent as the predominating factor of concussion in various linearinduced impact scenarios. Through the development of various impact test conditions using bicycle helmets on a biofidelic test headform and Hybrid III neck, it was determined that the correlation between the linear and rotational accelerations experienced by the head is affected in part by the impact situation. Additionally, while linear accelerations may be adequate predictors of concussion in some impact scenarios, it was determined that there are situations in which the rotational accelerations would be the more dominating factor in the expected probability of concussion.