Now showing 1 - 2 of 2
- PublicationA Comparison of dynamic impact response and brain deformation metrics within the cerebrum of head impact reconstructions representing three mechanisms of head injury in ice hockeyIce hockey has been identified as having one of the highest concussion rates. The three most likely causes of concussive injury are; falls to the ice, shoulder to head impacts and punches to the head. The purpose of this study was to examine how these three mechanisms of injury in the sport of ice hockey influence the dynamic response of the head form and the magnitude and distribution of maximum principal strain in the cerebrum. The three impact mechanisms were simulated using a Hybrid III head and neck form attached to a linear impactor, pendulum or monorail system. Three dimensional linear and rotational acceleration data from each impact condition were used to undertake finite element modeling to calculate maximum principal strain in regions of brain tissue. The results indicated that each mechanism incurred a unique peak resultant linear and rotational acceleration response. The maximum principal strain magnitudes were found to be largest in the fall to the ice. The regions of the brain incurring the largest deformation varied per mechanism of injury. This variation of peak magnitude per brain region might explain the differences in symptomology for concussion. Furthering the understanding of these mechanisms would aid in improving the safety of the game.
- PublicationCharacterization of persistent concussive syndrome using injury reconstruction and finite element modellingConcussions occur 1.7 million times a year in North America, and account for approximately 75% of all traumatic brain injuries (TBI). Concussions usually cause transient symptoms but 10 to 20% of patients can have symptoms that persist longer than a month. The purpose of this research was to use reconstructions and finite element modeling to determine the brain tissue stresses and strains that occur in impacts that led to persistent post concussive symptoms (PCS) in hospitalized patients. A total of 21 PCS patients had their head impacts reconstructed using computational, physical and finite element methods. The dependent variables measured were maximum principal strain, von Mises stress (VMS), strain rate, and product of strain and strain rate. For maximum principal strain alone there were large regions of brain tissue incurring 30 to 40% strain. This large field of strain was also evident when using strain rate, product of strain and strain rate. In addition, VMS also showed large magnitudes of stress throughout the cerebrum tissues. The distribution of strains throughout the brain tissues indicated peak responses were always present in the grey matter (0.481), with the white matter showing significantly lower strains (0.380) (p<0.05). The impact conditions of the PCS cases were severe in nature, with impacts against non-compliant surfaces (concrete, steel, ice) resulting in higher brain deformation. PCS biomechanical parameters were shown to fit between those that have been shown to cause transient post concussive symptoms and those that lead to actual pathologic damage like contusion, however, values of all metrics were characterized by large variance and high average responses. This data supports the theory that there exists a progressive continuum of impacts that lead to a progressive continuum of related severity of injury from transient symptoms to pathological damage.
435Scopus© Citations 51