College football players are more likely to sustain concussions during the preseason and during practices than in the regular season or during games, according to a new study that examines strategies for preventing repeat injuries. Researchers examined data recorded with helmet sensors worn by 658 college football players who experienced a total of 528,684 head impacts between 2015 and 2019. Overall, players sustained a median of 415 head impacts per school year, including both games and practices during the preseason and regular season, with 68 confirmed concussions. A total of 33 concussions (48.5%) occurred during the preseason, even though this accounted for just 20.8% of the total playing time. This translates into a daily concussion rate of 0.059 per team in the preseason vs 0.016 per team in the regular season. "The higher incidence of concussion in the preseason is likely due to several factors, including the total hours and intensity of training, heavy emphasis on full contact drills with tackling and blocking, and the volume of participants in those activities," said lead study author Michael McCrea, a professor and co-director of the Center for Neurotrauma Research at the Medical College of Wisconsin in Milwaukee. "Over the course of the season, it's common for football teams to reduce the frequency of full contact drills, thereby also reducing head impact exposure and risk for concussion from full contact activities," McCrea said by email. The study also found that most concussions (72%) occurred during practices, not during games. And, when researchers looked at total head impact exposure (HIE) - including concussions as well as other blows to the head recorded by helmet sensors that didn't result in a concussion diagnosis - they still found the preseason and practices more dangerous from a head injury perspective. Preseason HIE rates were almost twice the rates during the regular season (324.9 vs 162.4 per team per day). Roughly two-thirds of HIEs occurred during practices (66.9%). When researchers looked only at injuries during the regular season, they still found HIE rates were 84.2% higher during practices than games (median 175.0 vs 95.0 impacts per player per season). "The overall number of practices and the volume of players participating in those drills compared to games suggests that reducing full contact activities in practice could do the greatest good in reducing incidence of head impact exposure and concussion throughout the full football season, not just the preseason," McCrea said. One limitation of the study is that researchers lacked video footage to independently verify head impacts detected by the helmet sensors, the study team notes in JAMA Neurology. The study also didn't report total hours of exposure to allow for a calculation of injury rates based on the total amount of time athletes were on the field during practices versus games, or during the preseason versus the regular season. Even so, the results underscore the importance of training protocols that minimize head contact, said Christopher Nowinski, co-founder and chief executive of the Concussion Legacy Foundation, who coauthored an editorial accompanying the study. "In my opinion, there should be no more than 15 minutes of full contact per week during the season, all head impacts should be monitored by sensors, and we should set strict limits on how many head impacts players are allowed to incur in practice," Nowinski said by email. —Lisa Rapaport Source
