1. Comparing the Incidence of Head Impacts Sustained in
Conference versus Non-Conference Women’s Soccer Games
Acors CD*, Bradney DA*, Breedlove KM†, Bowman TG*:
*University of Lynchburg, VA, †University of Michigan, Ann Arbor
INTRODUCTION
Interest in investigations examining head impacts in women’s soccer has increased recently due to collegiate women’s soccer players sustaining an average of 2-7 head impacts per game.1
In soccer, head impacts can be common due to heading the ball which is an integral part of the sport.
The incidence rate for sustaining head impacts is higher in collegiate women’s soccer players compared to their high school counterparts.2
RESULTS
Out of the 568 verified head impacts, 201 were sustained during conference games and 367 were sustained during non-conference games.
Participants sustained more head impacts during non-conference games (IR= , CI95= ) compared to conference games (IR= , CI95 = ; IRR =2.30, CI95= ).  
Game type did not alter the combined dependent variables (F2,565= 2.00,  P=0.45, 𝜼2<.01, 1-𝛽=.19).
 Follow up ANOVAs showed game type failed to alter linear accelerations (F1,566=1.51) and rotational accelerations (F1,566=1.41).
DISCUSSION & CONCLUSIONS
Our findings suggest that collegiate women’s soccer players sustained more head impacts while competing in non-conference games compared to conference games.
Previous research has also shown that head impact magnitudes are not altered by type of game play in soccer.1
Although head impact biomechanics should not be used diagnostically,3 recording head exposures in collegiate women's soccer is important for informing rule implementation that could improve player safety.
We recommend future research that examines if head impacts in youth girls’ and professional women’s soccer differ based on game details.
We speculate that the higher frequency of head impacts sustained in non-conference contests could be attributed to the players engaging in risky behavior during non-conference contests since conference contests determine postseason participation.
PURPOSE
Our aim was to determine frequency and magnitude differences in head impacts sustained by collegiate women’s soccer players during conference and non-conference games.
METHODS
Participants included 24 intercollegiate women’s soccer players (age=19.65±1.27 years, height=165.80±4.87 cm, mass = 64.45±7.38 kg).
Game type served as the independent variable. Frequency, peak linear acceleration (PLA), and peak rotational acceleration (PRA) were the dependent variables.
We measured frequency and magnitude differences of head impacts with the X2 Biosystems xPatch sensors that participants wore during every practice and game.
We used video footage of all practices and games to confirm all head impacts over a 10 g threshold during a 3 year period.
Frequency differences were determined by calculating incidence rates (IRs) and incident rates ratios (IRRs) with corresponding 95% confidence intervals (CI95).
We used MANOVA in order to examine magnitude differences.
REFERENCES
Lamond LC, Buckley TA,Kaminski TW. Linear acceleration in direct head contacts across impact type, player position, and playing scenario in collegiate women’s soccer players. J Athl Train. 2018;53(2):
McCuen E, Svaldi D, Breedlove K, Kraz N, Cummiskey B, Traver J, et al.Collegiate women’s soccer players suffer greater cumulative head impacts than their high school counterparts. J Biomech. 2015;48(13):
O’Connor KL, Rowson S, Duma SM, Broglio SP. Head-impact measurement devices: a systematic review. J Athl Train. 2017;52(3):
Figure 1. Mean Rotational Acceleration Across Conference vs Non Conference Games
Figure 2. Mean Linear Accelerations Across Conference vs Non Conference games
ACKNOWLEDGEMENTS
We would like to thank the Percy Wootton Student-Faculty Research Award and the Schewel Research Fund from the University of Lynchburg for  providing funding to complete this project.
Figure 3. Applied xPatch Sensor
Figure 4.Percentages of Head Impacts Sustained During Games