Relationships between Aggression and Head Impact Kinematics in Ice Hockey

Abstract

Sustaining head impacts in sport regularly may be damaging to long-term neurological health. Further, some research has suggested a relationship between sports aggression and concussion, therefore, being able to identify players at-risk of sustaining these head impacts may be beneficial in monitoring their safety on ice. PURPOSE: To examine relationships between player self-reported aggression in ice hockey and head impacts sustained in a collegiate club season. METHODS: Nineteen collegiate male ice hockey (19.9±1.2 years old, 1.8±0.06 m, 78.5±5.7 kg) players completed the Competitive Anger and Aggression Scale (CAAS), a valid 12-item survey used to evaluate anger and aggression during sport competition. Penalty minutes (PM) and games played (GP) statistics were taken from the official game records. Head impact kinematics were recorded via tri-axial accelerometers (Triax, Nowalk, CT) that each player wore for games/practices. Spearman correlation was performed to examine relationships between CAAS scores, PM, GP, and head impact kinematic variables (number of impacts, mean linear and rotational acceleration, and cumulative linear acceleration). RESULTS: Neither CAAS scores (mean anger: 26.8±4.9, aggression: 22.2±7.3) nor PM (mean 20.9±22.7, range: 0-95) were significantly related to any other variables. GP was significantly correlated with number of impacts (r=0.606, p=0.006), mean rotational acceleration (r=0.583, p=0.009), and cumulative (r=0.542, p=0.02). Mean number of impacts was 71.5±51.6 (range: 6-168); mean linear and rotational acceleration were 36.8±3.8g and 3.5±0.7 krad/sec2. CONCLUSIONS: The main finding is no relationship between self-reported anger and aggression during sport and/or sustaining penalty minutes and head impact kinematics, which suggests that hockey athletes who play with more intensity do not necessarily sustain more head impacts while playing. Unsurprisingly, GP was related to impacts, suggesting that more playing time is related to sustaining more and/or greater head impacts. CAAS and PM as markers of playing aggression may not be helpful in determining athletes who sustain more head impacts.