The Relationship Between Head Impact Kinematics And Player Position In Youth Football

Repetitive head impacts (RHIs) are common in youth tackle football. We hypothesize that the magnitude of RHIs differ between football playing positions. PURPOSE: To determine differences in magnitude of RHIs across various football player positions in 3rd through 6th grade athletes throughout a youth football season. METHODS: Athletes (N = 68, age = 10.2 ± 1.0 years, height = 145.1 ± 10.8 cm, mass = 40.5 ± 9.1 kg) wore custom-fit mouthguards, containing a tri-axial accelerometer and gyroscope for seven tackle football games. Impacts over 10 g that were video-verified and classified by Prevent Biometric’s proprietary algorithm as true positives were included for analysis. The peak linear acceleration (PLA) and peak rotational velocity (PRV) was analyzed using generalized estimating equations with a gamma distribution and a log link function to compare RHIs across positions. RESULTS: PLA was lower in Offensive Line athletes compared to Defensive Line athletes (Table 1). For other positions, the differences in PLA were not statistically significant (p > 0.05). Running Back, Receiver, and Linebacker athletes had higher PRV compared to Defensive Line athletes, while Quarterback and Offensive Line athletes had lower PRV (Table 1). The difference in PRV for Secondary athletes compared to Defensive Line athletes was not statistically significant. CONCLUSION: Position-specific differences in PLA and PRV may be a result of the movement patterns required by each position. Offensive Line athletes typically focus on maintaining their position and blocking, while Defensive Line athletes often initiate contact while attempting to break through the Offensive Line, therefore moving at greater velocity, which may lead to higher PLA and PRV. Similarly, Running Backs, Receivers, and Linebackers are involved in more open-field play, where they may experience higher-speed collisions, resulting in higher PRV. - Position Total RHIs Median PLA Exp(B) p Median PRV Exp(B) p Defensive Line 62 13.4 Referent Referent 7.55 Referent Referent Quarterback 7 15.6 0.92(0.8-1.05) 0.224 5.2 0.79(0.72-0.86) <0.001* Running Back 20 13.3 1.10(0.76-1.58) 0.618 11.3 1.50(1.20-1.88) <0.001* Receiver 9 15.1 0.92(0.77-1.09) 0.309 11.9 1.40(1.13-1.73) 0.002* Offensive Line 25 12.3 0.79(0.68-0.91) 0.002* 4.6 0.63(0.51-0.79) <0.001* Linebacker 33 15.1 1.15(0.94-1.4) 0.182 8.7 1.18(1.09-1.29) <0.001* Secondary 7 19.7 1.02(0.83-1.26) 0.834 7.3 1.16(0.76-1.79) 0.492 Table 1