Neck and Trunk Strength Training to Mitigate Head Acceleration in Youth Soccer Players

Abstract

Müller, C and Zentgraf, K. Neck and trunk strength training to mitigate head acceleration in youth soccer players. J Strength Cond Res XX(X): 000-000, 2020-Heading in soccer involves repetitive head accelerations that may be detrimental for brain health. One way to mitigate adverse effects may be to increase head-neck stabilization and thus reduce the kinematic response after intentional headers. This study aimed to (a) assess associations between neck strength and head kinematics and (b) evaluate an exercise intervention designed to increase strength and attenuate head acceleration during intentional heading in youth soccer players. In 22 athletes, we used accelerometers to assess associations between neck strength and peak linear acceleration (PLA). We attached the accelerometers to the occiput and sternum, allowing us to differentiate between total, trunk, and head PLA. Longitudinally, we evaluated the effects of a 14-week twice-weekly resistance training in a subsample of 14 athletes compared with regular soccer training (N = 13). Results showed that female athletes had lower isolated neck strength (p ≤ 0.004), lower functional neck strength (p ≤ 0.017), and higher total PLA during purposeful headers compared with males (17.2 ± 3.5 g and 13.0 ± 2.3 g, respectively, at 9.6 m·s ball velocity during impact; p = 0.003). The intervention group showed moderate to large strength gains ( = 0.16-0.42), resulting in lower PLA (total -2.4 g, trunk -0.8 g, and head -1.5 g) during headers. We conclude that a resistance training focusing on cervical and trunk musculature is practicable in youth soccer, elicits strength gains, and helps to mitigate PLA during purposeful heading. Results should encourage youth strength and conditioning professionals to incorporate neck exercises as a risk reduction strategy into their training routine.