Repetitive Head Impacts In Youth Tackle Football: First Year Athletes Compared To Experienced Athletes

There is concern regarding when children should start tackle football. Parents may consider factors like player age and size to determine their child’s readiness for football. However, prior research has not explored the effect of these factors on repetitive head impact (RHI) exposure. PURPOSE: The purpose of this study is to compare number and amplitude of RHIs between first year players and experienced players over an entire football season. This study also explored the effect of player age and size on RHI number and amplitude within first year players. METHODS: Youth football players (8-12 years old) wore instrumented mouthguards to record the number and amplitude of RHIs (> 10 g) for all games and practices across one season. Mouthguards were fitted using standard boil-and-bite methods. RHIs were confirmed by video verification. Football experience was self-reported. We used analysis of covariance to compare primary outcome measures (number of RHIs, median peak linear acceleration [PLA], median peak rotational acceleration [PRA]) between first year and experienced players while controlling for age and body mass index (BMI). We also used multiple regression analyses to examine the association between age, BMI, and primary outcome measure within first year players. RESULTS: The number, PLA, and PRA of RHIs did not differ between first year (number = 36 ± 25; PLA = 16.33 ± 1.51; PRA = 1864 + 307) and experienced players (number = 46 ± 26, p = .224, ηp2 = .026; PLA = 16.02 ± 1.33, p = .736, ηp2 = .002; PRA = 1689 ± 298, p = .097, ηp2 = .048). Within first year players, BMI (p = .039 R2 = .123) but not age (p = .566, R2 = .01) was associated with number of head impacts; however, age (PLA = p = .017, R2 = .161; PRA = p = .010, R2 = .183) but not BMI (PLA = p = .708 R2 = .004; PRA = p = .688 R2 = .005) was associated with PLA and PRA. CONCLUSIONS: Despite lack of prior football experience, first year players experienced a similar number and amplitude of RHIs as experienced players. Within first year players a higher BMI was associated with a lower number of head impacts, which may be a result of player position and heads up tackle training. Younger age was associated with higher PLA and PRA, which suggests an opportunity for younger athletes to improve tackling techniques. Supported by Ohio State’s Chronic Brain Injury Program, Pilot Award; NIH/NINDS Loan Repayment Program