Evaluation of Head Kinematics, Force-strain Models, and Correlation of MRI Markers With Neurocognitive Testing in Youth Soccer Heading

Despite the large popularity of soccer worldwide and in the US, the majority of research on sport-related head impacts has been concentrated in male American football players using head-impact measurement sensors in instrumented football helmets. The limited research in soccer players likewise has focused on males, particularly those playing at an elite level, such as collegiate or professional. Unfortunately there is a paucity of data on youth soccer athletes in regards to how these younger players actually head the ball and what forces they experience. Measurement of head impacts is essential to further understanding the potential risks associated with heading in youth soccer, and to further inform rule or policy changes that limit head impact exposure in these younger age groups.

Specific Aim: Establish and validate age-based head kinematics, force-strain models and brain injury probability maps from sensor worn data during soccer heading tasks.

In this study, age-and sex-specific force strain models will be validated using a study of soccer headers under controlled conditions. Youth soccer players in 6th-12th grade will be recruited to participate in a header training session while wearing motion sensor headbands. All children will undergo MRI scanning and baseline assessment of neurocognitive function, psychological health, and academic aptitude and performance. Participant-specific finite element models will be created from MRI scans, and principle tissue strains will be determined based on head motion profiles during soccer headers and compared between age- and sex-specific groups.

High fidelity head kinematics will be acquired during soccer headers under controlled conditions using a custom headband embedded with multi-axis motion sensors. MRI scans will be obtained in all participants, and individualized and population averaged (to reduce computational burden), whole brain tractographs will be created. New participants-specific finite element models will be generated using geometry-adaptive mesh morphing techniques to match the head morphology of each subject using a baseline FE head model (to reduce model development time). The linear and angular acceleration histories obtained from the pre- and post-training soccer heading tasks will be applied directly to the FE models to simulate the head motion of each participant. The principal strains will be determined for each heading task, and brain injury probability maps will be generated based on the resulting tissue strain. Brain injury risk will be assessed through the incorporation of a cellular injury criterion embedded into the finite element simulations, with smaller strains correlating with lower injury risk. Soccer header force-strain relationships will be compared between age groups, and pre-and post-training session. This analysis will provide insight into the effect of age and training on improving heading techniques and reducing the risk of injury.