Article Text
Abstract
Objective To evaluate the effect of player aggression on head impact biomechanics.
Design Prospective cohort.
Setting Field (on-ice) study.
Participants Thirty-seven volunteer ice hockey players (age=15.0±1.0 years, height=173.5±6.2 cm, mass=66.6±9.0 kg, playing experience=2.9±3.7 years).
Interventions Participants were equipped with accelerometer-instrumented helmets to collect head impact biomechanics for one playing season. The Buss-Perry Aggression Questionnaire (BPAQ) was administered to all players. We collected the total number of penalties in minutes (PIM) throughout the season. Data were analysed using random intercept general mixed linear models, with each individual player as a repeating factor/cluster.
Main Outcome Measurements Dependent variables included linear and rotational head accelerations, and the Head Impact Technology severity profile (HITsp), a weighted composite score factoring impact accelerations, duration, and location. Tertile aggression and PIM data were used to categorise players into high, moderate, and low aggression levels.
Results The players who experienced the highest number of PIM experienced greater rotational accelerations (p=0.034) and HITsp values (p=0.046) than those with the lowest number of PIM. No differences in linear acceleration for PIM were observed (p>0.05). We did not observe any differences between the aggression levels as measured by the BPAQ (p>0.05).
Conclusions Youth ice hockey players with higher PIM experienced greater head impact forces, supporting behavioural interventions designed to reduce excessive penalty taking among youth hockey players such as Fair Play in North America. Officials should more stringently assess penalties to participants who purposefully foul opponents. Our results should encourage youth ice hockey players to conform to playing rules.
Acknowledgements This study was supported in part by a grant from the Ontario Neurotrauma Foundation to The University of North Carolina at Chapel Hill Injury Prevention Research Center (grant #2005-PREV-BANT-387). The USA Hockey Foundation and the National Operating Committee on Standards for Athletic Equipment (NOCSAE) also provided financial support.
Competing interests None.