Background There is debate as to whether protective headwear should be mandated in female lacrosse; however, a lack of quantitative evidence exists regarding the effectiveness of, and case for, protective headwear in female lacrosse.

Objective To compare head impacts in male and female lacrosse in terms of rate recorded by headband-mounted sensors and mechanism determined by video analysis.

Design Prospective observational study.

Setting One season of suburban high school female (12 games) and male (15 games) lacrosse competition.

Participants Adolescent female (n=15) and male (n=33) lacrosse players.

Main Outcome Measurements Head impact rate as calculated by the number of video-confirmed head impacts above 16 g recorded by SIM-G (Triax Technologies) headband-mounted impact sensors divided by the number of player-games during one season. Mechanism of impact (i.e. player contact, fall, stick-to-head or ball-to-head) determined by detailed video analysis of sensor-recorded events.

Results For male lacrosse, 226 head impacts were recorded during 272 player-games for an impact rate of 0.83 impacts per player-game. The most common mechanism for head impacts to male lacrosse players was player contact (57%) followed by stick-to-head (27%), falls (15%) and ball-to-head (2%). For female lacrosse, 7 head impacts were recording during 109 player-games for an impact rate of 0.06 impacts per player-game. Of the seven head impacts to female lacrosse players, three were player contact (43%), three were stick-to-head (43%) and one was a fall (14%).

Conclusions The impact rate for female lacrosse players is less than 8% of the rate for male lacrosse players, which suggests that head impacts in female high school lacrosse are rare. However, nearly half of the head impacts in female lacrosse were stick-to-head, for which protective headwear may reduce the risk of injury. Therefore, further investigation of the association between head impact mechanism and injury in female lacrosse is required.