Frequency and Location of Head Impacts in Division I Men's Lacrosse Players.
Miyashita T, Diakogeorgiou E, Marrie K, & Danaher R. Athletic Training and Sports Health Care. 2016;8(5):202-208.
Take Home Message: Player position and session type such as practice or game are the main factors that influence head impact frequencies and magnitudes for lacrosse athletes.
The number of concussions continues to rise, and one of the sports with the greatest increase is men’s lacrosse. Men’s lacrosse is an equipment-intensive and high contact sport; however, little research has been conducted to identify the frequency of head impacts lacrosse athletes sustain over a season. Therefore, the authors collected head impact data from 42 Division I men’s lacrosse athletes to investigate the frequency and location of head impacts. The athletes wore an accelerometer in the jaw guard of their helmets during 17 games and 40 practices to track the frequency and location of head impacts. The athletes sustained a total of 11,403 impacts with an average of 52.8 g of linear acceleration. During practices, the athletes experienced 5,759 impacts (144 impacts per practice) resulting in 3.4 impacts per player per practice. In addition, out of the 17 games, the athletes sustained 5,644 impacts (332 impacts per games) resulting in 7.7 impacts per player per game. While there were 2.3 times more impacts occurring during games than practices, the average magnitude of these impacts were lower during games. The authors also found that midfielders sustained the most impacts and goalies suffered the greatest magnitude of impacts. Impacts to the front of the head were the most common and generated the highest magnitudes of impacts.
The results show that player position, and session types were largely determinant of head impact frequencies and magnitudes for these athletes. These findings are beneficial to healthcare providers, helmet manufacturers, and lacrosse officials, to familiarize them with the characteristics of repetitive head impacts in the sport of lacrosse. Further, these findings have the potential to aid in injury prevention and promote safer rule changes in college lacrosse. While this study did not report concussion incidence, it does describe the commonality of head impacts in the sport. This study has some limitations, primarily due to a lack of video validation for the impacts recorded by the accelerometers. This suggests that some of the head impacts recorded may not have been directly related to game or practice scenarios, but rather from dropping their helmets or post-goal celebrations. Many of the magnitudes reported were under 50g, which calls to question if these impacts are large enough to cause a pathophysiological disturbance to the brain, and if research is any closer to understanding the impact thresholds that result in concussion. Although there were a lot of impacts reported in this study, many of them resulted in low magnitudes and none of them were validated through video analysis. This suggests that the true head impacts the athletes actually sustained during participation may be lower than what the authors report. Despite these limitations, this study represents an important step in the need to better understand the biomechanical characteristics of repetitive head impacts in college lacrosse.
Questions for Discussion: Do you diagnose more concussions in lacrosse goalies and midfielders compared to other positions? What do you notice are most common mechanisms of concussions in the sport of lacrosse? Do you think these sensors are a clinically useful tool? Do you think that the placement of the accelerometer in the jaw guard as opposed to in the helmet itself, affects the results of this study?
Written by: Patricia Kelshaw, MS, LAT, ATC
Reviewed by: Jane McDevitt