Head impact telemetry in football and correlations with neurophysiological impairment

Abstract

A growing body of evidence indicates that concussions depend not only on a single offending head impact, but also on the series of subconcussive head impacts prior to concussion. Talavage et al. have shown that several subjects in their cohort of high school football players exhibit substantial changes in their neural health due to subconcussive blows without developing any outward symptoms. They probed neural health through the use of functional magnetic resonance imaging (fMRI). Breedlove et al. subsequently demonstrated that changes in fMRI correlate with the number and location of head impacts experienced throughout the football season. This work builds upon the analysis of Breedlove et al. Regression models based on an updated and expanded data set are presented. This analysis confirms that the number and location of subconcussive head impacts are factors in eliciting deleterious changes in neural health as measured by fMRI. Further analysis indicates that the peak linear acceleration of head impacts is also a factor in eliciting changes in fMRI. Collectively, these results indicate that the subconcussive injury mechanism is analogous to mechanical fatigue or soft tissue overuse injury. Furthermore, comparison of player head impacts based on position (i.e., linemen versus skill positions) indicates that player position may be a risk factor for subconcussive injury due to the large number of head impacts characteristic of linemen. These analyses help elucidate the connection between head impact biomechanics and subconcussive pathophysiology. Analyses indicate that improvements in football equipment and changes in coaching and rules would likely have a protective effect in the prevention of subconcussive and concussive injury in football