Youth football players sustain concussions at about the same rate in practice and overall as high school and college athletes, but are injured at a rate 3 to 4 times higher than older players during games, reports a 2013 study.  (1)

It was the study's suggestion that recent limits placed by some youth football organizations on the amount of full-contact practice may be counterproductive, however, that has proven the most controversial, generating a firestorm of protest from concussion researchers and youth football organizations.

Findings

Researchers from the University of Pittsburgh and Cornell University tracked 468 participants, 8-12 years of age, from 4 youth tackle football leagues in Western Pennsylvania over the course of a single season.  Here's what they found:

• No multiple concussions: Researchers recorded 20 medically-diagnosed concussions involving 20 different participants; 
• Most in games: Of the total, only 2 occurred during practice while 18 were sustained during games;
• Higher overall concussion rate than in high school or college football.  The overall concussion injury rate for youth football games was 1.76 per 1,000 AEs (athletic exposures; 1 AE = participation in a game or practice). This is a rate higher than reported for high school (2,3,4) (see table below) and college football (2,5)
• Comparable injury rate for practices: The injury rate for practices (.24 per 1,000 AEs) was comparable or even lower than for high school players (.21 to .31 per AEs) (2,3,4) and college players (0.39 per AEs)(2);
• Dramatically higher injury rate during games: 
  • The injury rate for games (6.16 per 1,000 AEs) was much higher than for high school players (2,3) and and those playing college football (2)
  • Overall, youth football players were an astounding 26 times more likely to suffer a concussion in a game than in practice.  By comparison, the ratio for high school and college football players was around 7 times more likely (2,3);
• Older players injured at a higher rate:
  
  • 15 of the 20 concussions were suffered by 11- and 12-year-old players;
  • The combined practice and game injury rate for 8- to 10-year olds was .93 per 1000 AEs, slightly higher than the rates found in three prior studies for high school players (.47, .60 and .64 per 1,000 AEs respectively)(2,3,4) and in two studies of college players (.37 and .61 per 1,000 AEs)(2,5)
  • 11- and 12-year old players were almost 3 times more likely to sustain a concussion than players aged 8 to 10 years;
• Players at skilled positions most vulnerable: All but one of the 20 concussions involved players in skilled positions (eg, running back, quarterback, linebacker).  Researchers observed that there were 1-2 players on the teams in the study who accounted for the majority of tackle and contact/collisions.  Identifying such players, and possibly player rotations, were suggested as ways to possibly mitigate concussion risk.
• Helmet-to-helmet contact was principle injury mechanism: 
  • 45% of concussions involved head-to-head contact;
  • 5% were head-to-ground
  • 5% were head-to-body
  • 45% involved an unknown injury mechanism due to context of play (i.e. large group tackling with unclear mechanism)

Youth football deemed 'generally safe'

From the data, lead author Anthony Kontos, assistant research director for the University of Pittsburgh Medical Center (UPMC) sports concussion program, and colleagues concluded that "youth football is a generally safe activity with regard to concussions for children aged 8-12 years, particularly during practice."

More significant than the study's actual findings, however, was the assertion by Kontos and his colleagues that reducing contact exposures in youth football during practice - such as done in 2012 by Pop Warner [1] (6) - "may not only have little effect on reducing on reducing concussions but may also actually increase the incidence of concussions in games via reduced time learning proper tackling in practice" (emphasis supplied).  A  "better approach to reducing concussions in youth football," they suggested, "may be to focus on awareness and education" such as via the CDC's and USA Football's Heads Up concussion programs.

Controversial findings

With so much at stake (approximately 3 million youth play tackle football annually, along with 100,000 collegiate, and 1.3 million high school participants (1)), and with so much unknown about concussions, the study has, not surprisingly, generated considerable controversy in both the medical and football communities.

Expanding on the study's main finding, Michael Collins, a study co-author and executive and clinical director of the UPMC concussion program seem to go out of his way in an interview with the Pittsburgh Post-Gazette [2] to criticize Pop Warner: "limiting contact at practice in Pop Warner is short-sighted," he said, "because practice is an opportunity to teach proper technique, for kids to learn how to do this the right way." 

Of the 18,000 concussion patients who visit the UPMC clinic every year, Collins said, "the worst cases I see are kids who on August 15 ... decide to go out for football without ever learning the sport.  The don't know how to tackle or play, they get lit up."  

No surprisingly, there was immediate pushback from Pop Warner. Julian Bailes, M.D., co-director of the NorthShore University HealthSystem Neurological Institute in Chicago and chair of Pop Warner youth football's medical advisory board, told USA Today [3] that the study's suggestion that Pop Warner had gotten it wrong when it moved in 2012 to limit contact in practices [1] was "erroneous" and sent a "bad message" to players, coaches, and parents. 

Bailes told the Post-Gazette [2], "Those who played and coached the game know it's very possible to still teach technique without going head-to-head full contact. If they're implying you need head-to-head full contact to learn proper technique, I disagree and think they are erroneous in that conclusion." 

Indeed, Bailes went so far as to tell USA Today that "to think more hitting your brain is good for you or doesn't make any difference if you do it in practice is asinine."

Also expressing reservations about the study's main conclusion was Bennett Omalu, MD, one of the leading forensic pathologists in the field, well-known for his post-mortem research on head trauma.  "The very basic medical principle, research or no research, is 'Do no harm,'" Dr. Omalu told the Post-Gazette.

"Anybody who tells me that willfully exposing the brains of children to repeated impact is something good, I would humbly disagree with that person. I am not an advocate for the idea that football should be banned or not played -- I am not that extreme. I stand with Pop Warner, and I stand with caution. Limit the exposure of children from repeated blows to the head in whatever activity they do." 

While not surprised by the study's finding that the vast majority of concussions occur in games, Jon Butler, executive director of Pop Warner, was not expecting the UPMC researchers' suggestion that not enough contact in practice may be detrimental. "It surprises me that they say limiting contact in practice may have a reverse effect, essentially," Butler told USA Today [4], noting that much of the teaching of proper tackling technique is done at slow speeds without full contact.    

Calling the kettle black?

Surprisingly, neither Bailes, Omalu, nor Butler criticized the study for making the logical leap in implying a cause-and-effect relationship between the amount of practice time and the concussion rate in youth football games that data collected, essentially by Collins' own admission, simply cannot support.  

Collins suggested that Pop Warner had acted in 2012 to limit contact practices precipitously, "without there being a shred of scientific data." At the same time, however, he admitted that more research was needed, including whether youth sports teams that implement USA Football's Heads Up football program have fewer concussions. In doing so, Collins, for all practical purposes, acknowledged that the data in the current study did not support its broad conclusion because in order to establish that that the amount of time spent in practice learning to tackle leads to more concussions in games, much less that reducing the amount of time spent learning to tackle in practice makes matters worse, the study would have had been designed from the start to test those hypotheses, which it simply did not.

Thus for Collins to criticize Pop Warner, because "It's science. It's not getting up and talking about doing this and doing that without having evidence," when the data in the study simply does not support a finding of a cause-and-effect relationship, one could argue, is a case of the pot calling the kettle black.  

Talking past each other?

Closer examination of the positions staked out by Kontos and Collins, on the one hand, and by Bailes, Omalu, and Butler, on the other, suggests. however, that, despite the overheated rhetoric, their positions are not as diametrically opposite as first appears, and that the solution, as if often the case, probably lies somewhere in the nuanced middle.

Kontos was quick to tell USA Today that Bailes was misreading what the study said. "We don't want more head-to-head contact. What we want is more contact practices where we teach proper technique to avoid head-to-head collisions in games. And, if we don't have good practices to teach that, we're sending kids out unprepared to make those tackles."  

This is precisely what experts on the teaching of tackling recommend, including Coach Bobby Hosea, whose heads-up tackling technique has been adopted by USA Football and is featured in MomsTEAM's high school football concussion documentary, "The Smartest Team [5]."  

Sadly, such are the high stakes in the politically-charged world of concussions in football that, even when there is general agreement, in this case, that kids need to learn how to tackle safely, the UPMC researchers and the study's critics come off sounding like arch-enemies.

Limiting contact to reduce exposure to sub-concussive hits

Also lost in the back-and-forth between Kontos and Bailes et al is another very important point: that reducing the amount of contact during practices - as is now being done, to a greater or lesser extent, at all levels of football - from the pros to college football (e.g. Ivy League, [6] and, the Pac-12 [7], and, most recently, in a recommendation from the NCAA) to the high school level [8] (Arizona, Washington State, Iowa, Texas, and California [9], among others, have all recently moved to limit the number of full-contact practices in spring football or during the regular season, or eliminate them altogether) to Pop Warner [1] - is intended not just to reduce the number of concussions during practice, but also to limit the amount of total brain trauma sustained as a result of repetitive sub-concussive hits [10].

Repetitive, low-impact hits have been linked in a number of recent studies in football [10](7,8,9) and in soccer [11] (10) to short- and possibly long-term brain damage. A 2012 Virginia Tech study [12] found that youth football players are sometimes subjected to hits as hard as their bigger, faster and older counterparts at the high school and college level.  (11) 

To be fair, Kontos and his co-authors do make a point of noting in their study that "we know little about the potential for long-term effects from repetitive exposures to subconcussive impacts that might occur in practices and games. As such, we cannot discount the potential effects of reducing practice exposures on effects related to repetitive subconcussive impacts."  Yet, one wonders why, if that was the case, they elected to take such an obvious swipe at Pop Warner without all the facts.   

Taking into account both the risk of injury from concussion and that from repetitive sub-concussive blows, the challenge for both scientists and youth sports organizations is thus to find a way to somehow perform a delicate balancing act: to reconcile two competing demands: to minimize contact practice in order to reduce the number of concussions sustained in practice and repetitive sub-concussive impacts that emerging science suggests may have a deleterious long-term health effects [13], while at the same time maximizing the amount of contact practice, time that is needed to maximize the protective effect of proper tackling on the number of concussions players sustain in game action.

Study limitations

Kontos admitted that the study, believed to be the first of its kind to study concussion rates at the youth football level, was limited by several factors:

• the sample size (468 players on 22 teams; 11,338 AEs of which 8,415 were practice and 2,923 were games) was small for a epidemiologicall study [Note: a much larger study commissioned by USA Football, the results of which are expected to be issued in the first quarter of 2014, involves nearly 2,000 youth football players on more than 100 individual teams, and generated more than 60,000 AEs in just its first year alone); 
• it was geographically limited (youth football players in Western Pennsylvania) and thus may not reflect trends in other geographic regions of the country [Note: the USA Football study is monitoring 10 youth football leagues of varying size and demographics in six states: Arizona, Indiana, Massachusetts, Ohio, South Carolina, and West Virginia]; 
• the surveillance period was short (only a single season)[Note: The USA Football study is being conducted over two years];
• concussion injury rates in practice may have been underestimated because access to medical personnel during practices was much more limited than during games, when licensed medical professionals (e.g. emergency medical technicians, physicians) were present to assess and manage athletes suspected of having sustained a concussion, forcing researchers to rely on potentially unreliable reports from coaches - who all received preseason concussion education and were contacted 2 or 3 times per week to determine if any suspected concussion occurred during practices - instead of the certified athletic trainers or physicians who recorded data for the high school and college studies of concussion rates (2-5)
• observation during games was hampered by the fact that personnel was typically at field level or just 1 to 3 meters above field level, which likely explained the inability to identify the injury mechanisms in fully 45% of the concussions.  

Preventing concussions and reducing the amount of trauma resulting from repetitive sub-concussive blows is also just one piece of a larger concussion puzzle.

Just as daunting a challenge is to identify athletes with suspected concussion so they can be removed from practice or game action, and not allowed to return to play (RTP) until their brains have been given a chance to fully heal.  

This is an issue of particular concern in youth football, where there generally are no certified athletic trainers or other medical personnel on the sideline trained to spot the often subtle, sometimes even undectable, signs of concussion [14], and make the all-important decision to remove a player from a practice or game designed to minimize the risk of a delayed recovery and long-term problems.

No wonder that, as the Post-Gazette put it, "the conclusion on whether parents should allow or encourage children to play tackle football remains stuck in a place nobody wants it to be -- without a definite answer and with more research still needed."

In other words, to paraphrase The Eagles, the more we know, the less we understand. 

Update: In a 2013 study (12), researchers at Wake Forest Baptist Hospital and Virginia Tech found that less contact during practice could mean a lot less exposure to head injuries among young football players and the kind of repetitive subconcussive blows that some researchers suggest can lead to long-term brain injury, but does not result in exposure to higher impact hits during games. [

Researchers measured the number, force, location, and effect of blows to the head in 50 youth-league players ages 9 to 12. Their study followed a 2012 study (11) of small group of youth players, ages 7 to 8, in which they found that most high impact hits occurred during practice, not games. That study prompted Pop Warner to swiftly move to impose limits on the time spent in full-contact practice.

The new study involved one team that, while not affiliated with Pop Warner, chose to follow its new practice rules, and two others that did not. Significantly, the data showed that reducing the number of head hits in practice did not, as the study by the UPMC discussed in this article (1) predicted, lead to higher force impacts during games.

1. Kontos P, Fazio V, Burkart S, Swindell H, Marron J, Collins M. Incidence of Sport-Related Concussion among Youth Football Players Aged 8-12 Years. J Pediatrics 2013. DOI 10.1016/j.jpeds.2013.04.011

2. Gessel L, Fields S, Collins C, Dick R, Comstock RD.  Concussions among United States high school and collegiate athletes in 20 sports. J Athl Train 2007;42:495-503.

3. Marar M, McIlvain N, Fields S, Comstock R. Epidemiology of concussion among United States high school athletes in 20 sports. Am J Sports Med 2012;40:747-755.

4.  Lincoln AE, Caswell SV, Almquist JL, Dunn RE, Norris JB, Hinton RY.  Trends in concussion incidence in high school sports: a prospective 11-year study.  Am J Sports Med 2011;39:958-63.

5. Hootman J, Dick R, Agel J. Epidemiology of collegiate injuries for 15 sports: summary and recommendations for injury prevention initiatives.  J Athl Train 2007;42:311-319.

6.http://www.popwarner.com/About_Us/Pop_Warner_New/Rule_Changes_Regarding_Practice___Concussion_Prevention_s1_p3977.htm

7. Talavage T, Nauman E, Breedlove E, et. al. Functionally-Detected Cognitive Impairment in High School Football Players Without Clinically-Diagnosed Concussion. J Neurotrauma 2010; DOI: 10.1089/neu.2010.1512.

8. Bazarian JJ, Zhu T, Blyth B, Borrino A, Zhong J. Subject-specific changes in brain white matter in diffusion tensor imaging after sports-related concussion. Magnetic Resources Imaging 2012; 30(2): 171-180.

9. March N, Bazarian JJ, Puvenna V, Janigro M, Ghosh C, et. al. Consequences of Repeated Blood-Brain Barrier Disruption in Football Players. PLoS ONE 2013;8(3): e56805. doi: 10.1371/journal.pone.0056805.

10. Lipton M, Kim N, Zimmerman M, Kim M, Stewart W, Branch C, Lipton R. Soccer Heading Is Associated with White Matter Microstructural and Cognitive Abnormalities. Radiology 2013;DOI:10.1148/radiol.13130545.

11. Daniel R, Rowson S, Duma S. Head Impact Exposure in Youth Football. Ann. Biomed Eng 2012;40(4):976-981.

12. Cobb BR, Urban JE, Davenport EM, Rowson S, Duma SM, Maldjian JA, Whitlow CT, Powers AK, Stizel JD. Head Impact Exposure in Youth Football: Elementary School Ages 9-12 Years and the Effect of Practice Structure. Ann Biomed Eng ( 2013): DOI: 10.1007/s10439-013-0867-6 (online ahead of print)

Posted June 25, 2013, upated August 2, 2014 

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