Concussive Head Impact Biomechanics in NCAA DIII Women’s Lacrosse and Soccer Athletes Hallie Sayre

Introduction Head impacts and concussions are a major health concern (McCrea, 2004) Impacts to the head have been confirmed as the leading cause of concussions in sports (Crisco, 2011) An estimated 3.8 million concussions occur in the U.S. each year in athletics (Broglio, 2014) Head impact sensors are being used in order to aid in the diagnosis and recognition of concussions (Guskiewicz, 2011) There is limited research regarding the biomechanics of concussion in women’s sports

Methods Participants: Data collection: 2 NCAA DIII women’s lacrosse athletes 2 NCAA DIII women’s soccer athletes Data collection: All participants wore the X2 Biosystems xPatch as apart of a larger study The participants reported to their athletic trainer if they experienced any concussions symptoms All concussions were confirmed by the athletic trainer and a physician We then gathered information regarding the concussive event and reviewed the impact data and film from the day of injury to confirm the concussive event and specific head impact

Results

Participant 1 Participant 2 Participant 3 Participant 4 Sport Women's Soccer Women's Lacrosse Peak LA (g) 55.86 19.08 15.78 76.52 Peak RA (deg/s2) 321,665.00 310,928.00 154,308.00 686,178.00 Impact Location Front Side Duration (ms) 12 9 10 17 # of impacts on day of concussion 7 1 5 Cumulative LA on day of concussion 220.02 108.61 167.53 Cumulative RA on day of concussion 2,870,017.10 844,096.70 1,430,748.90

Results

Discussion Our concussed participants suffered impacts with lower magnitudes than those reported in literature. These thresholds were developed using the HIT system which relies on helmet acceleration to estimate head acceleration. (Mihalik, 2016) While both the HIT system and xPatch tend to over predict the linear acceleration of a head impact, the HIT system over predicts the linear acceleration to a much larger degree than the xPatch. (Mihalik, 2016)

Discussion Two impacts with the same peak linear or rotational acceleration could be quite different from an energy standpoint Women’s lacrosse athletes are not able to have contact with other players, thus shifting the impact from body to body contact towards more impacts with the ball and/or stick

Conclusion The variability within our results indicate that the use of helmet and/or head mounted sensors for diagnosis of concussions should be cautioned against Any head impact indicator must demonstrate that is has predictive value (Mihalik, 2016) This is hard to do since the incidence of concussion is low relative to the large number of head impacts and the heterogeneous range of biomechanical values associated with concussions (Mihalik, 2016) These results suggest concussions are heterogeneous from a mechanism standpoint, especially across sex We speculate the differences in the RA and LA between the women’s soccer and lacrosse athletes can be attributed to the differences in style of play