Limiting or eliminating contact practices in football would result in an 18% to 40% reduction in head impacts respectively over the course of a high school football season, reports a new study, [1] which says that, until the risk factors for chronic traumatic encephalopathy [1] (CTE) are better defined, and research shows that reducing the time spent learning to tackle in practice will not lead to increased risk of concussions in games, policymakers should proceed with caution in imposing such limits.
While describing the goal of reducing the overall number of head impacts that high school football players sustain in a season as "logical" and "appealing," lead author, Steven P. Broglio, PhD, ATC, of Michigan NeuroSport and Director of the NeuroSport Research Laboratory at the University of Michigan, concluded that, "until the risk factors for CTE are better defined by carefully designed and controlled research," and research determines "what the advisable limit to head impact exposure should be," employing contact limits or establishing "hit counts [2]" will remain "educated guesses, at best."
Repetitive, low-impact hits (i.e. sub-concussive impacts [3]) have been linked in a number of recent studies in football [3], [2-5] hockey, [4] and soccer [4] [6] to short- and possibly long-term brain damage. Given the potentially large number of head impacts a high school football athlete may experience over the course of the season and their career, some experts have suggested implementing head impact monitoring and impact limitation strategies similar to pitch counts [5] in baseball.
Until technology makes it practical and feasible to equip cash-strapped football teams with low-cost sensors [6] to measure the number, direction and force of head impacts during games and practices, some have suggested reducing the number of contact practices permitted each week as a way of reducing athletes' overall head impact burden.
In response, limits on full-contact practices have begun to implemented at every level of football, from the National Football League to college football (i.e. Ivy League, [7] and Pac-12 [8]) to the high school level (Arizona [9], Washington State [10], Iowa, and Texas [11] have all recently moved to limit the number of full-contact practices, either in spring football or during the regular season), and down to the youth level (Pop Warner [12]). All are intended to limit the amount of total brain trauma football players sustain as a result of repetitive sub-concussive hits [3].
While the recent movement to limit full-contact practices is intended to make the game safer, some experts agree with Broglio that caution should be the byword [13]. A March 2013 review of current risk-reduction strategies in the British Journal of Sports Medicine [7] reminds state high school athletic associations and legislatures that, in enacting rules such as limits on full-contact practices, they "need to carefully consider potential injury 'trade-offs' associated with the implementation of injury-prevention strategies, because every change may have certain advantages and disadvantages. That is, by reducing one risk or danger, additional risks may be created." In other words, as the Michigan study points out, limits on full-contact practices could create additional risk of injury to players because they haven't spent enough time learning to tackle properly.
Anecdotal evidence suggests that at least some high school football players are against limiting full-contact practices for much the same reason. A completely unscientific survey of Newcastle (OK) players during the filming of the concussion documentary, "The Smartest Team, [14]" suggest that they were concerned that it might expose them to more, not less injuries. One told producer and director Brooke de Lench that he felt that "if you went out at practices, didn't have contact, didn't have near the amounts of impacts you receive in the game, it would almost be a surprise to you when you got to Friday night."
Not surprisingly, there are those who believe limits on full-contact practices, taken too far, could do just that, among them experts like Coach Bobby Hosea, whose heads-up tackling technique is being implemented at all levels of the game. [8] As Hosea observes about practice, "If you want to be better at playing an instrument, you need more practice, not less. A new lanquage? More not less. So, why are we limiting practice?"
While recognizing that less tackling practice may reduce the over all number of head impacts, Hosea suggests that, "without changing the way tackling is taught, nothing will change. Only practicing smarter will." Hosea argues that "teaching athletes proper tackling mechanics that keep the head out of the collision will eliminate impacts to the head altogether."
As Coach Hosea says in the PBS documentary, "The Smartest Team: Making High School Football Safer," [14], It's "time to have a standardized tackling progression all across the board. Right now tackling is a ‘Heinz 57' approach. Whatever your grandfather taught your dad, that's what you're teaching them. But we know now, that's antiquated. There's things that are dangerous. So number one, educate the coaches."
He points out that the Michigan study suggests that players were still learning to tackle the old-fashioned way, referring at one point to the fact that non-contact practice sessions centered on player technique and plays with athletes "wrapping up" their opponent. Ironically, claims Hosea, athletes "wrapping up" their opponents is the actually the "primary reason" helmet-to-helmet contact occurs in the first place. "Eliminating that instruction will eliminate crown-first impacts from practice and games," he argues. Another way to cut down on the number of hits to the head in practice, he to use tackling dummies and blocking sleds while learning to tackle, instead of live players.
The issue of contact practice limits has generated significant contoversy. Researchers at the University of Pittsburgh Medical Center suggested, based on data showing that youth football players sustained concussions at about the same rate in practice and overall as high school and college athletes but suffered concussions in games at a rate 3 to 4 times higher than older players during games, [9] that Pop Warner's limits on full-contact practice might be counterproductive.
Indeed, expanding on the study's main finding, Michael Collins, a study co-author and executive and clinical director of the UPMC concussion program, went even further; in an interview with the Pittsburgh Post-Gazette [16], Collins went so far as to say that such limits were "short-sighted, 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, pushback to the study and Collins' remarks from Pop Warner was immediate. 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 [17] that the study's suggestion that Pop Warner had gotten it wrong when it moved in 2012 to limit contact in practices [12] was "erroneous" and sent a "bad message" to players, coaches, and parents.
Bailes told the Post-Gazette [16], "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 UPMC 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 [18], noting that much of the teaching of proper tackling technique is done at slow speeds without full contact.
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."
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."
A subsequent study by researchers at Wake Forest Baptist Medical Center and Virginia Tech seems to support the positions staked out by Bailes, Omalu and Butler, suggesting 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 [3] that some researchers suggest can lead to long-term brain injury, without increasing exposure to higher impact hits during games. [10]
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 UPMC predicted, lead to higher force impacts during games.
"The concern is if we don't teach kids how to hit in practice, they're going to get blown away in the games," said Stefan Duma of the School of Biomedical Engineering and Sciences and one of the co-authors of the study, in an interview with The New York Times. "This shows you can dramatically cut the amount of exposure in practice and have no more exposure during the games."
The challenge for youth sports organizations is thus to find a way to somehow perform a delicate balancing act, reconciling two competing demands: to minimize contact practice in order to reduce the number of concussions sustained in practice and the number of sub-concussive impacts that emerging science suggests may have a deleterious cumulative effect [19] on a player's cognitive function over the long term, while at the same time maximizing the amount of time in practice learning how to tackle and block without head-to-head contact, time that is needed to maximize the protective effect of proper tackling on the number of head-to-head hits players sustain in game action, which can not only result in concussion, but catastrophic neck and spine injuries.
"As a scientist, I am not in a position to make policy," Broglio told MomsTEAM, but "we can't just reduce [the number of contact practices] without looking at the whole picture. We don't know if 18% means anything, or how much less [in terms of the number of impacts] is meaningful."
If he were making policy, however, Broglio would "lean more towards the cautious side" in limiting contact practices, which is not to say that he doesn't think "that a football program could be successful" with some limits on full-speed contact practices. Pointing to rugby, where players practice tackling without helmets without increased risk of head injury in games, he "didn't necessarily buy" the argument advanced by some experts that limiting contact practices would expose football players to increased injury risk in games. As Broglio writes in the study, however, that view comes with a very important caveat: only if "extra emphasis on the appropriate tackling technique [is] put in place to ensure that the highest level of safety was maintained during games."
To determine the effect policies to limit full-contact practices may have on the number and magnitude of head impacts at the high school level, Broglio and his colleagues evaluated impact data collected as part of an ongoing investigation of head impact biomechanics in high school football, selecting data from the 2009 season, as it was believed to represent the maximum season length for high school football: 7 days of preseason practice, including a scrimmage, 9 weeks of the regular season (2 noncontact practice sessions, 2 contact practice sessions, and 1 game), and 5 weeks of postseason play (1 noncontact practice, 3 contact practices, and 1 game) including the state championship game.
Analyzing the data collected using 1-year-old Riddell Revolution helmets equipped with the HITS system, an array of 6 single-axis accelerometers used to track and record linear and rotational acceleration, impact location and HITsp value (a unit-less measure of impact magnitude incorporating linear and rotational acceleration, impact location, impact duration using a weighted formula), Broglio and his colleagues at the University of Michigan found that:
The Michigan study points to recent research suggesting that the number of head impacts sustained may play a more important role in putting an athlete at risk of developing CTE than clinically evident concussions. Among them are studies of athletes in football [2,3,4,5] and ice hockey [4] found to have subtle changes in cerebral function in the absence of concussion symptoms or clinically measurable cognitive impairment which researchers linked to the volume of head impacts, and a much publicized case-study autopsy of a collegiate football player, Owen Thomas, with no reported history of concussions, which revealed early signs of CTE. [11]
"If verified," Broglio writes, these reports "would support the use of head impact numbers to limit the head trauma volume experienced by an athlete each season."
But, while recognizing that "contact sport athletes appear to be at a greater risk for developing CTE," he was careful to note the absence of studies "indicating the relationship between head impacts, concussions, and other factors (eg. genetic profile) that may trigger the disease pathway." Until the risk factors for developing CTE are better defined, Broglio says, the effect of reducing impacts by 18% to 40% in the risk for CTE is "unknown" and strategies designed to reduce those risks will necessarily remain "an educated guess, at best."
"Ultimately, a comprehensive approach that includes, but is not necessarily limited to, modifications of head impact exposure, equipment modifications, rule changes and enforcement, and changes in game culture may all be needed to reduce injury risk," Broglio concludes.
1. Broglio SP, Martini D, Kasper L, Eckner JT, Kutcher JS. Estimation of Head Impact Exposure in High School Football: Implications for Regulating Contact Practices. Am J Sports Med 2013;20(10). DOI:10.1177/036354651302458 (epub September 3, 2013).
2. Breedlove EL, Robinson M, Talavage TM, et al. Biomechanical correlates of symptomatic and asymptomatic neurophysiological impairment in high school football. J Biomech. 2012;45(7):1265-1272.
3. Talavage TM, Nauman E, Breedlove EL, et al. Functionally-detected cognitive impairment in high school football players without clinically diagnosed concussion. J Neurotrauma. 2013;doi:10.1089/neu.2010.1512 (e-publ April 11, 2013)
4. 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.
5. 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.
6. 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.
7. Benson B, McIntosh A, Maddocks D, et. al. What are the most effective risk-reduction strategies in sport concussion? Br J Sports Med 2013;47:321-326.
8. Alan Schwarz, "Teaching Young Players A Safer Way To Tackle." New York Times, December 25, 2010 (http://www.nytimes.com/2010/12/26/sports/football/26tackling.html?pagewa... [20])9. 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
10. 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)
11. McKee AC, Stein TD, Nowinski CJ, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013;136(Pt 1):43-
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Links:
[1] https://mail.momsteam.com/node/3289
[2] https://mail.momsteam.com/node/4406
[3] https://mail.momsteam.com/node/4492
[4] https://mail.momsteam.com/node/6208
[5] https://mail.momsteam.com/node/816
[6] https://mail.momsteam.com/node/6264
[7] https://mail.momsteam.com/node/3583
[8] http://espn.go.com/college-football/story/_/id/9338542/pac-12-limit-hits-contact-football-practice
[9] http://www.prweb.com/releases/2013/4/prweb10637189.htm
[10] http://www.bellevuereporter.com/sports/204181201.html
[11] http://www.dallasnews.com/sports/high-schools/headlines/20130421-uil-committee-recommendation-limits-in-season-full-contact-high-school-football-practice.ece
[12] http://www.popwarner.com/About_Us/Pop_Warner_News/Rule_Changes_Regarding_Practice___Concussion_Prevention_s1_p3977.htm
[13] https://mail.momsteam.com/node/6041
[14] http://www.thesmartestteam.com
[15] http://fast.wistia.net/embed/iframe/auaumzmmua?popover=true
[16] http://www.post-gazette.com/stories/news/health/upmc-concussions-study-less-contact-in-youth-football-practice-doesnt-help-690574/#ixzz2VRhizwlr
[17] http://www.usatoday.com/story/sports/2013/06/08/pop-warner-football-concussions/2404007/
[18] http://www.usatoday.com/story/sports/2013/06/05/study-concussion-risk-low-in-football-practice/2394775/
[19] https://mail.momsteam.com/node/5481
[20] http://www.nytimes.com/2010/12/26/sports/football/26tackling.html?pagewanted=all&_r=0
[21] https://mail.momsteam.com/node/6246
[22] https://mail.momsteam.com/sub-concussive/sub-concussive-hits-growing-concern-in-youth-sports
[23] https://mail.momsteam.com/health-safety/youth-football-concussion-study-generates-controversy-over-suggestion-that-limiting-contact-practices-mistake
[24] https://mail.momsteam.com/health-safety/sports-concussion-safety/concussions-by-numbers/head-hits-can-be-reduced-in-youth-football-study-says
[25] https://mail.momsteam.com/health-safety/seven-ways-to-reduce-risk-of-brain-trauma-in-contact-and-collision-sports
[26] https://mail.momsteam.com/concussive-and-subconcussive-blows-may-speed-up-brain-natural-aging-process-studies-suggest
[27] https://mail.momsteam.com/5-7/limiting-hits-head-in-youth-sports-aim-innovative-hit-count-program
[28] https://mail.momsteam.com/sports/study-finds-head-impacts-among-high-school-football-players-greater-than-collegiate-level