Numerical Reconstruction of Real-Life Concussive Football Impacts

FRECHEDE, B., and A. S. MCINTOSH. Numerical Reconstruction of Real-Life Concussive Football Impacts. Med. Sci. Sports Exerc., Vol. 41, No. 2, pp. 390-398, 2009. Purpose: To present a protocol of numerical reconstructions of concussive events in football using MADYMO. To refine the knowledge of the dynamics associated with these events. Methods: Twenty-seven cases of concussive head impacts involving unhelmeted Australian football and rugby players were simulated Using MADYMO. The cases had been previously analyzed using a video analysis protocol and were fully reconstructed for the purpose of this study. The reliability of these reconstructions had been previously assessed using a sensitivity analysis of the influence of several independent variables on the dynamical outputs. The use of a complete human model enabled consideration for morphometry, initial movements of the players, and an accurate estimate of the effective masses involved in the impacts. Results: Mean peak values for concussion were found to be 103g for the head center of gravity linear acceleration, 8022 rad.s(-2) for the head angular acceleration, and 359 for the head impact criterion. An estimate of the average effective energy transferred to the head was 47 J. With the severity grading used in this study, the head impact power was found to be the best predictor of concussion severity. Conclusions: These biomechanical results compare well with other studies. They should contribute to the identification of the energy levels at which concussive impacts occur in football for the purpose of a better evaluation of protective devices in these sports.