Investigating Risk and Protective Factors for Repetitive Head Impact Exposure in Law Enforcement Cadets. - PROJECT SUMMARY Law enforcement training and job duties can expose law enforcement cadets (LECs) to repetitive head impacts (RHIs). During the training academy, LECs complete weeks of subject control technique training, including defensive tactics training and boxing. These are designed to test the LEC’s critical thinking, train acute stress management, and teach proper use of force under pressure. However, these RHIs have the potential to result in mild traumatic brain injuries (mTBIs), which can lead to behavioral changes, impaired cognitive performance, and alterations to neural structure and function. These types of training drills cannot be eliminated, despite their potential for RHIs, as having defensive skills is a critical component of law enforcement job performance. The goal of this project is to inform modifications in training schedules and injury mitigation strategies within the training academy, and ultimately safeguard operational capability and career longevity of LEOs by the following specific aims. Aim 1. To determine if male sex is a risk factor for higher HAE exposure in LECs. Aim 2. To determine if greater neck strength is a protective factor for lower HAE exposure in LECs. Aim 3. To determine if better visual-motor function is a protective factor for lower HAE exposure in LECs. I will be successful in completing the proposed research plan with the support and mentorship I will receive from my mentorship team. Dr. Caccese (sponsor) will provide expertise in RHI monitoring and concussion research, enhancing my understanding of best practices in this field. Dr. Jeffrey Wing (co-sponsor) will provide statistical analysis and interpretation expertise, to further my understanding and application of concepts learned in didactic statistical coursework. Dr. Di Stasi (co-sponsor), an excellent clinician-scientist with a successful track record in securing research funding, will assist in both my clinical and scientific development to attain my long-term goal of being a leading clinician-scientist in the concussion research field. She will provide guidance in how to translate the results from this proposed research to intervention studies as I begin my career. Dr. Onate (co-sponsor) has expertise in clinical treatment of tactical athletes and research, supporting the foundation of the proposed training and research plan. He will also provide constructive feedback and education on my mentorship and leadership skills. This training and research plan will be conducted at The Ohio State University (OSU), a world-class research organization and a multifunctional hub of clinical and basic science research. I will have access to the several centers under the umbrella of OSU, including the School of Health and Rehabilitation Sciences, the Sport and Tactical Athlete Injury Resiliency Science Lab, the Chronic Brain Injury Program, and the Human Performance Collaborative. As a result of my mentor’s participation in the above centers, I will have the support that is integral to both my training and research plan, and my career development as a productive, independent clinician-scientist.