Poster P12 - Differences between youth football practice activities and head kinematics following an intervention

Introduction: American football is a popular sport with over 2.8 million youth athletes between the ages of 6 and 13 participating annually. Cumulative head impact exposure from contact in football can result in structural and functional changes to the brain, which remains a prevalent public health concern. Youth football athletes spend almost triple the amount of time in practice sessions during a normal football season week compared to competition sessions. Coach directed practice activities (i.e., practice drills) can influence head acceleration events (HAE) both in frequency and magnitude, and can be targeted interventions. This study aimed to evaluate the preliminary effectiveness of an intervention (COmmunities Aligned to reduce Concussion and Head impact exposure; COACH) to reduce head impact exposure and concussion risk.

Materials and

Methods: One 12U (≤ 12 years) and two 13U (≤ 13 years) level football team were recruited for the control arm of the study during the 2021 and 2022 seasons. Control teams followed coach-prescribed practice activities in practices. After COACH was developed, two teams (12UI, 13UI) were identified to pilot test COACH during the 2023 season. Intervention teams attended a pre-season coaches’ clinic, created practice plans, utilized a booklet aligned with North Carolina state guidelines for contact in practice, and were paired with a high school head coach peer mentor during season as part of COACH. The state guidelines recommend use of the five levels of contact (Air, Bag, Control, Thud, and Live), recommending no more than 15 minutes of Live contact (i.e., full speed tackling) per week. Athletes participating on each team were instrumented with mouthpieces measuring head impact biomechanics. A member of the research team noted the beginning and end of each session along with the start and end times and names of the drills conducted during the session. Linemen and non-linemen athletes were grouped separately. Head kinematic data from events collected by the mouthpiece sensors were reviewed alongside the time-synchronized video. Minutes of live time, rate of head acceleration events, and the distribution of head kinematics were compared between intervention and control seasons.

Results, Conclusions, and Discussions: Head acceleration data were collected for an entire season from n=35 athletes enrolled on three control teams across two seasons, n=12 athletes enrolled on the 12UI team, and n=13 athletes enrolled on the 13UI team. Coaches of the 13UI team implemented COACH for the entire season. Coaches of the 12UI team implemented COACH for the first four weeks of the season until the head coach (and organizational leader) left the organization. At week 6 of the intervention season, the head coach of the 12UI team left the team, and the assistant coaches quickly increased the amount of live time and stopped adhering to the intervention. Data collected from the team prior to the week 6 change was denoted as 12UI adherent (A) while data collected after week 6 was denoted as 12UI non-adherent (NA). The 13UI team followed the intervention for the duration of the season. After video-verification and data reviewing, a total of 4,916 HAEs were classified as true positive (e.g., a mouthpiece sensor recorded an event that was visible on camera) during the control seasons; a total of 2,138 HAEs were classified as true positive from the intervention season. The time each group spent in live drills on a per session basis and the differences in head acceleration events (HAE) collected per athlete per session for each team is presented in Figure 1.

Preliminary data suggest COACH was effective at reducing HAEs experienced by athletes during a single football season. The 13UI and 12UI-A spent less time on Live drills than control teams. The 12UI-NA team spent similar time on Live to the control teams. Teams that participated in the intervention experienced fewer HAEs per athlete per session than controls. Organizational capacity influenced adoption and sustainment of the intervention program as evidenced by the intervention 12U team. In addition, coach turnover remains an external factor that can impede implementation. Future work will include a large-scale pragmatic trial to fully assess the effectiveness of COACH, while monitoring factors that influence implementation.

Acknowledgements (Optional): We thank the youth football organization for participating, and Tina Strates for assisting with this study. NIH NICHD (K25HD101686) funded this study.