Repetitive Head Impacts: A Concern At All Levels of Sports


Lindsey Barton Straus

Question of balance

Finding a way to reconcile two competing demands - minimizing contact in practice in order to reduce the number of concussions sustained and the number of hits players sustain over the course of a week and a season that emerging science, now more than ever, suggests may have a deleterious cumulative effect 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 - is challenging, but clearly not impossible.

"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 his 2013 study, however, his 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." 

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 bywordA March 2013 review of current risk-reduction strategies in the British Journal of Sports Medicine [11] 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. 

The results of at least two recent studies, however, suggest that reductions in full-contact practices can be accompished safely without putting players at additional risk, while researchers continue looking for the head trauma "holy grail": a threshold - whether it is number of hits per week, over the course of the season, of a certain force, or to a certain part of the helmet  (e.g. facemask, top of the head) above which players are at an unacceptably high risk of permanent brain injury.

First, a 2013 study by researchers at Wake Forest Baptist Hospital and Virginia Tech [24] showed that reducing the number of head hits in practice did not, as some had predicted[25]lead to higher force impacts during games. 

And, more recently, a 2015 study [39] reported that comprehensive coach education in teaching "heads up" tackling and practice contact restrictions, such as implemented by Pop Warner, can be effective in reducing the rate of concussions in youth football. 

Can behavior modification reduce the number of repetitive head impacts?

The preliminary results of study by researchers at the University of New Hampshire also suggest that the amount of RHI in football can be reduced by having the players engage in a 5-minute helmetless tackling drill twice a week during pre-season football and once a week during the season, a practice regimen which was found to reduce by almost a third the frequency of impacts to the head over the course of a single season.

In the study, 50 football players at the University of New Hampshire were assigned to an intervention (25 athletes) or control (25 athletes) group. The intervention group participated in five-minute tackling drills without their helmets and shoulder pads as part of the Helmetless Tackling Training (HuTT) program.

Drills occurred twice per week during preseason practices and once per week over the course of the 16-week season. The control group performed noncontact football skills with no change to their routine. All athletes were provided head-impact patch sensors worn on the skin and new helmets. Both groups were supervised by members of the football coaching staff.

Researchers found that, after just one season, the helmetless-tackling training intervention resulted in a 28% reduction in head-impact frequency per athletic exposure (e.g participation in a game or practice) by the end of the season, while the control group's head impacts remained the same.  At the end of the season, the intervention group experienced an average 30 percent fewer impacts per exposure than the control group.

High school and college football players can each sustain more than 1,000 impacts in a season, while individual youth players may sustain 100 during that same time frame, according to the study.  Unlike other methods being employed to mitigate the amount of RHI, such as by limiting the number of allowable contact practices, and by altering game rules (such as penalizing hits to defenseless receivers), none of which directly address the common fundamental cause: impacts to the head, and, in the case of efforts directed at improving helmet technology, by promoting a false sense of security, may perpetuate - rather than eliminate - the use of the head as the point of contact during play, the helmetless tackling drills seek to reduce RHI by modifying the behavior of the players.

"The notion that removing the football helmet for discrete and regular periods during practice to reduce head-impact frequency is counterintuitive to the sport," writes Erik E. Swartz, PhD, ATC, FNATA, lead author of the study and professor and chair of the Department of Kinesiology at the University of New Hampshire.

"These findings elucidate the risk-compensation phenomenon and may help explain the behavior of spearing and the rise in catastrophic neck and head injuries that followed [introduction of football helmets with hard polycarbonate shells in the 1950's and 60's],"  the study states.. "A football helmet is designed to protect players from traumatic head injury, but it also enables them to initiate and sustain impacts because of the protection it affords. While improving protective equipment in and of itself will not resolve the risk of concussion and spine injury in football, the solution may be found in behavior modification." 

"The extent to which this intervention may yield similar outcomes in younger players with less experience is still unknown," says Swartz. and modifications may be required to realize a positive effect.  To that end, he noted that researchers were currently in the first year of a study testing the helmetless-tackling training program at four high schools in New Hampshire,

"Should future research replicate our findings, the eventual adoption of helmetless-tackling training [may] improve public health and decrease the associated economic burden by reducing football-related head and neck injuries and the risk of long-term neurologic [injury]," Swartz said, which is "of vital importance for younger, more vulnerable populations."

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Originally posted April 6, 2012; most recently January 4, 2015