Novel research from the Concussion Assessment, Research and Education (CARE) Consortium sheds new light on how to effectively reduce the incidence of concussion and head injury exposure in college football.
Dr. Michael McCrea
The study, led by neurotrauma experts Michael McCrea, PhD, and Brian Stemper, PhD, professors of neurosurgery at the Medical College of Wisconsin in Milwaukee, reports data from hundreds of college football players across five seasons and shows
Dr. Brian Stemper
The research also reveals that such injuries occur more often during practices than games.
“We think that with the findings from this paper, there’s a role for everybody to play in reducing injury,” Dr. McCrea said. “We hope these data help inform broad-based policy about practice and preseason training policies in collegiate football. We also think there’s a role for athletic administrators, coaches, and even athletes themselves.”
The study was published online Feb. 1 in JAMA Neurology.
More injuries in preseason
Concussion is one of the most common injuries in football. Beyond these harms are growing concerns that repetitive HIE may increase the risk of long-term neurologic health problems including chronic traumatic encephalopathy (CTE).
The CARE Consortium, which has been conducting research with college athletes across 26 sports and military cadets since 2014, has been interested in multiple facets of concussion and brain trauma.
“We’ve enrolled more than 50,000 athletes and service academy cadets into the consortium over the last 6 years to research all involved aspects including the clinical core, the imaging core, the blood biomarker core, and the genetic core, and we have a head impact measurement core.”
To investigate the pattern of concussion incidence across the football season in college players, the investigators used impact measurement technology across six Division I NCAA football programs participating in the CARE Consortium from 2015 to 2019.
A total of 658 players – all male, mean age 19 years – were fitted with the Head Impact Telemetry System (HITS) sensor arrays in their helmets to measure head impact frequency, location, and magnitude during play.
“This particular study had built-in algorithms that weeded out impacts that were below 10G of linear magnitude, because those have been determined not likely to be real impacts,” Dr. McCrea said.
Across the five seasons studied, 528,684 head impacts recorded met the quality standards for analysis. Players sustained a median of 415 (interquartile range [IQR], 190-727) impacts per season.
Of those, 68 players sustained a diagnosed concussion. In total, 48.5% of concussions occurred during preseason training, despite preseason representing only 20.8% of the football season. Total head injury exposure in the preseason occurred at twice the proportion of the regular season (324.9 vs. 162.4 impacts per team per day; mean difference, 162.6 impacts; 95% confidence interval, 110.9-214.3; P < .001).
“Preseason training often has a much higher intensity to it, in terms of the total hours, the actual training, and the heavy emphasis on full-contact drills like tackling and blocking,” said Dr. McCrea. “Even the volume of players that are participating is greater.”
Results also showed that in each of the five seasons, head injury exposure per athlete was highest in August (preseason) (median, 146.0 impacts; IQR, 63.0-247.8) and lowest in November (median, 80.0 impacts; IQR, 35.0-148.0). In the studied period, 72% of concussions and 66.9% of head injury exposure occurred in practice. Even within the regular season, total head injury exposure in practices was 84.2% higher than in games.
“This incredible dataset we have on head impact measurement also gives us the opportunity to compare it with our other research looking at the correlation between a single head impact and changes in brain structure and function on MRI, on blood biomarkers, giving us the ability to look at the connection between mechanism of effect of injury and recovery from injury,” said Dr. McCrea.
These findings also provide an opportunity to modify approaches to preseason training and football practices to keep players safer, said Dr. McCrea, noting that about half of the variance in head injury exposure is at the level of the individual athlete.
“With this large body of athletes we’ve instrumented, we can look at, for instance, all of the running backs and understand the athlete and what his head injury exposure looks like compared to all other running backs. If we find out that an athlete has a rate of head injury exposure that’s 300% higher than most other players that play the same position, we can take that data directly to the athlete to work on their technique and approach to the game.
“Every researcher wishes that their basic science or their clinical research findings will have some impact on the health and well-being of the population they’re studying. By modifying practices and preseason training, football teams could greatly reduce the risk of injury and exposure for their players, while still maintaining the competitive nature of game play,” he added.
Through a combination of policy and education, similar strategies could be implemented to help prevent concussion and HIE in high school and youth football too, said Dr. McCrea.