Head impacts sustained by male collegiate water polo athletes

Water polo is a contact sport that is gaining popularity in the United States and carries a risk of repeated head impacts and concussion. The frequency and magnitude of sport-related head impacts have not been described for water polo. We aimed to compare patterns of empirically measured head impact exposure of male collegiate water polo players to patterns previously reported by a survey of current and former water polo athletes. Participants wore water polo caps instrumented with head impact sensors during three seasons of collegiate water polo. Peak linear acceleration (PLA) and peak rotational acceleration (PRA) were recorded for head impacts. Athlete positions were recorded by research staff at the occurrence of each head impact. Head impacts were sustained by athletes in offensive positions more frequently than in defensive and transition positions (246, 59.9% vs. 93, 22.6% vs. 72, 17.5%). 37% of all head impacts during gameplay were sustained by athletes playing the offensive center position. Impact magnitude (means +/- SD: PLA = 36.1 +/- 12.3g, PRA = 5.0 +/- 2.9 krads/sec(2)) did not differ between position or game scenario. Among goalies, impact frequency and magnitude were similar between games (means +/- SD: 0.54 +/-.51 hits/game, PLA = 36.9 +/- 14.2g, PRA = 4.3 +/- 4.2 krads/sec(2)) and practices (means +/- SD: 0.96 +/- 1.11 hits/practice, PLA = 43.7 +/- 14.5g, PRA = 3.9 +/- 2.5 krads/sec(2)). We report that collegiate water polo athletes are at risk for sport-related head impacts and impact frequency is dependent on game scenario and player position. In contrast, magnitude does not differ between scenarios or across positions.