Poster Session II, July 14th 2010 — Abstracts: Evaluation of American football helmet performance using finite element modelling

Abstract

Since the introduction of helmets in American football the rate of traumatic brain injuries (TBI) has decreased, however, the incidence of mild traumatic brain injury (mTBI) appears to be unaffected. Currently finite element driven research is beginning to shed light on the difference in mechanism between TBI and mTBI, focusing mainly on the effects of linear and angular acceleration. From this it is hoped that a method to prevent these injuries may be developed. The research presented here will use a helmet evaluation protocol developed at the University of Ottawa to analyze the performance of currently used American football helmets using a finite element model (FEM). A helmeted hybrid III headform, equipped with a 3-2-2-2 accelerometer array was impacted according to the developed protocol. The x, y and z linear and angular acceleration data was then used to power the FEM. The results indicate that both helmets perform similarly when evaluated on linear acceleration alone, but differ angularly. Linear acceleration results were well below proposed limits for brain injury; however the FE model indicated a 50% likelihood of mTBI. There were also situations where linear and angular acceleration was nearly identical, but had different strain results, indicating that peak values may not be the most important curve characteristic. The results support two conclusions: (1) Angular accelerations seem to be more influential in the creation of brain strains in this model, and (2) Designing helmets by linear acceleration alone may not be ideal when brain strains are considered to be a factor in mTBI.