ABSTRACT
CONTEXT: Addressing safe-play knowledge and player aggression could potentially improve ice hockey sport safety. OBJECTIVES: To compare (1) safe-play knowledge and aggression between male and female adolescent ice hockey players and (2) head-impact frequency and severity between players with high and low levels of safe-play knowledge and aggression during practices and games. DESIGN: Cohort study. SETTING: On field. PATIENTS OR OTHER PARTICIPANTS: Forty-one male (n = 29) and female (n = 12) adolescent ice hockey players. INTERVENTION(S): Players completed the Safe Play Questionnaire (0 = less knowledge, 7 = most knowledge) and Competitive Aggressiveness and Anger Scale (12 = less aggressive, 60 = most aggressive) at midseason. Aggressive penalty minutes were recorded throughout the season. The Head Impact Telemetry System was used to capture head-impact frequency and severity (linear acceleration [g], rotational acceleration [rad/s(2)], Head Impact Technology severity profile) at practices and games. MAIN OUTCOME MEASURE(S): One-way analyses of variance were used to compare safe play knowledge and aggression between sexes. Players were categorized as having high or low safe-play knowledge and aggression using a median split. A 2 × 2 mixed-model analysis of variance was used to compare head-impact frequency, and random-intercept general linear models were used to compare head-impact severity between groups (high, low) and event types (practice, game). RESULTS: Boys (5.8 of 7 total; 95% confidence interval [CI] = 5.3, 6.3) had a trend toward better safe-play knowledge compared with girls (4.9 of 7 total; 95% CI = 3.9, 5.9; F1,36 = 3.40, P = .073). Less aggressive male players sustained significantly lower head rotational accelerations during practices (1512.8 rad/s (2) , 95% CI = 1397.3, 1637.6 rad/s(2)) versus games (1754.8 rad/s (2) , 95% CI = 1623.9, 1896.2 rad/s(2)) and versus high-aggression players during practices (1773.5 rad/s (2) , 95% CI = 1607.9, 1956.3 rad/s (2) ; F1,26 = 6.04, P = .021). CONCLUSIONS: Coaches and sports medicine professionals should ensure that athletes of all levels, ages, and sexes have full knowledge of safe play and should consider aggression interventions for reducing head-impact severity among aggressive players during practice.