Repetitive Head Impacts In Youth Tackle Football Athletes By Years Of Experience

Youth tackle football athletes sustain hundreds of repetitive head impacts (RHIs) per year. One potential risk/protective factor is the athlete’s years of tackle football experience, as training may improve tackling technique. Purpose: To examine the association between years of youth tackle football experience and the frequency and severity of RHIs. Methods: Fifty-six youth tackle football athletes ages 8-12 years wore custom-fit instrumented mouthguards (IMGs) for one season. Eight games were video-verified to confirm RHIs recorded from the IMGs (>10 g) and to count the number of plays and games for each athlete. RHI count included all video-verified IMG recordings, while severity measures (peak linear acceleration [PLA] and peak rotational velocity [PRV]) included only video-verified impacts also deemed “true” by the IMGs’ proprietary algorithm. “False” impacts were excluded from the severity analysis due to potential kinematic errors from the IMG moving relative to the teeth. Generalized linear models were used to examine the relationship between experience level and all outcomes, controlling for age. Results: Table 1 displays descriptive statistics for each outcome measure. - Table 1 Outcome Measures Descriptive Statistics Mean Standard Deviation Median 25th percentile 75th percentile Exp(B) (95% confidence interval) RHIs/Game 1.87 2.04 1.10 0.25 3.00 1.394 (0.831-2.341) RHIs/Play 0.03 0.03 0.02 0.01 0.06 1.002 (0.994-1.010) PLA 15.5 6.5 13.9 11.7 15.8 1.13 (1.02-1.25) PRV 7.7 3.6 7.5 5.6 8.8 1.028 (0.880-1.202) Years of tackle football experience (mean = 0.893, standard deviation = 1.039) was not significantly associated with the number of RHIs/game (p = .209), the number of RHIs/play (p = .668), or PRV (p = .728). There was a significant but small relationship between experience and PLA (p = .024, exp(B) = 1.13, 95% confidence interval = 1.02-1.25), suggesting that each additional year of experience yields a 13% higher PLA. Conclusion: The results indicate years of experience do not strongly affect the frequency and severity of RHIs sustained in youth tackle football athletes. The significant but small relationship between experience and PLA suggests that athletes with more experience have higher PLA. This may result from more forceful and aggressive contact with another athlete or the ground. Supported by: R01HD110401