Head Impact Exposure in Youth Soccer and Variation by Age and Sex.

OBJECTIVE: To examine variation in head impact exposure (HIE) by age and sex in youth soccer.

DESIGN: Prospective cohort study.

SETTING AND PARTICIPANTS: Youth soccer athletes (11-14 years old) in local clubs.

EXPOSURES: Age and sex.

OUTCOME MEASURES: Head impact exposure measured using adhesive-mounted accelerometers during 1 month of soccer.

RESULTS: Forty-six youth athletes (54% female) participated. No athlete reported a concussion during the study. More males than females had at least 1 head impact ≥15 g (P = 0.02). Of those who sustained a head impact above the 15-g threshold (57%), females sustained HIE of greater magnitude than males (median 47.4 g vs 33.3 g, P = 0.04). Eighty-five percent of athletes on U14 teams had at least 1 head impact ≥15 g compared with 15% of athletes on U12 teams (P < 0.001). Poisson regression stratified by sex and controlling for team-suggested age effects were significant only for females (P = 0.02). There was significant variation in HIE by team. There were no decrements in concussion symptoms, health-related quality of life, or neuropsychological testing after 1 month of soccer play.

CONCLUSIONS: There is significant variation in HIE in youth soccer, which seems to be influenced by age and sex. Further studies are needed to better understand potential significance for injury prevention.