An Evaluation of the Riddell IQ HITS System in Prediction of an Athlete's Head Acceleration

This paper explores the accuracy of the Riddell IQ HITS system in predicting an athlete's head acceleration. The data will be useful in efforts made to determine methods of reducing the risk of concussion. A Hybrid III anthropomorphic head was instrumented with a triaxial accelerometer, fitted with a Riddell IQ HITS helmet, and dropped onto a hard steel plate at varying impact angles. The resulting accelerations were recorded and compared for each angle. High speed camera images were also examined to better analyze the rigid body motion of the helmet relative to the head. The results showed that the HITS system agreed with the measured Hybrid III accelerations at angles near the crown of the head, but did not agree well with most of the other angles, especially for oblique impacts near the side or back of the head. High speed images verified that this discrepancy was caused by the rigid body motion of the helmet relative to the head. The results also showed that the precision of the system depends strongly on the loading conditions of the impact. Further investigation is needed to determine the accuracy of the system for rotational acceleration.