The design of football helmets can effect concussion risk, finds a new study by some of the nation's top concussion researchers.
The study provides what the authors say is good clinical evidence that helmet design can lower the risk of concussion, not in a laboratory, but in games and practices, by showing that a helmet model introduced in 2000 provides better protection against concussion than an older helmet employing 20-year-old design technology.
But it leaves unanswered the practical question faced by football parents, coaches, and administrators as to whether a difference in concussion risk reduction exists between new helmet models incorporating such new design features, and does nothing to change the prevailing view that no helmet has yet been designed which can prevent all concussions.
Analyzing helmet sensor data on 1.2 million head impacts sustained by more than 1,800 football players on eight collegiate teams, along with the number of diagnosed concussions they suffered, over a six-year period between 2005 and 2010, researchers identified a 53.9% reduction of concussion risk associated with a newer model of Riddell helmet, the Revolution (helmet on left in photograph), compared to an older model Riddell helmet, the VSR4 (helmet on the right). The Technical note was published online in the Journal of Neurosurgery (Rowson S, Duma SM, et al 2014).
Not only did players wearing the VSR4 helmets have a per-impact concussion rate more than twice as high as the rate for those wearing the Revolution helmet (8.37 concussions per 100,000 head impacts versus 3.86 concussions per 100,000 head impacts), but they also experienced higher acceleration impacts more frequently, regardless of the position they played.
The study's authors, who included such leading concussion researchers as Kevin Guskiewicz of the University of North Carolina and Steven Broglio of the University of Michigan, attributed the results to the Revolution helmet doing a better job of attenuating impact energy transferred to the head, findings consistent with drop tests which showed that the Revolution was better than the VSR4 at reducing linear and rotational acceleration, the forces that cause concussion.
"From a biomechanical standpoint, the difference in concussion risk between helmets is logical," wrote study co-lead author, Stefan Duma, head of the Virginia Tech-Wake Forest School of Biomedical Engineering.
Because a "helmet modulates the energy transfer to the head during impact, which dictates the accelerations that the head will experience, helmets that do a better job of lowering head acceleration reduce concussion risk," he said.
While laboratory studies have shown that helmets reduce impact forces, few have evaluated the effectiveness of different helmet designs in reducing concussions in practices and games.
A 2006 study of 2000 high school players (Collins M, Lovell MR, et al 2006) reported that the Riddell Revolution reduced the risk of concussion by 31% compared to other helmets, but has been widely criticized as methodologically flawed for failing to account for impact exposure and the age of the non-Revolution helmet, and as marred by conflicts of interest because it was funded by Riddell.
Data reported by Duma and his Virginia Tech-Wake Forest colleague, Steven Rowson, in a 2012 letter in the Annals of Biomechanical Engineering (Rowson S, Duma SM. 2014) analyzed 9 years of head impact data collected from 308 players. It reported that the Revolution reduced the risk of concussion by 85% compared to the VSR4 helmet. The current study, said Duma, was designed to address the limitations of the 2006 Collins study, expand on the 2012 results with a larger sample size, and control as much as possible for other variables.
Because each player was provided with a new helmet of the two models under investigation, helmet age did not vary. Each of the eight teams had a team physician and athletic trainers to monitor and evaluate players during games and practices, and the same team doctor made each concussion diagnosis throughout the study period.
"Most importantly," said Duma, by controlling for the number of head impacts each player experienced, which previous studies have shown varies by player and position, researchers were able to make an apples-to-apples comparison based on better data for addressing the question of whether helmet design can influence concussion incidence than the total number of players or athletic-exposures (e.g. number of games and practices).
The data "illustrates that differences in the ability to reduce concussion risk exist between helmet models in football," the authors concluded.
Our results are grounded on "very sound science," Duma asserted, and provide "solid clinical evidence" that helmet design, while it may never prevent all concussions from occurring in football, can reduce the incidence of this injury. [For the full text of Lindsay Barton's email interview with Professor Duma, click here ] Micky Collins, Director of the Sports Medicine Concussion Program at the University of Pittsburgh Medical Center, and author of numerous peer-reviewed concussion studies, including the 2006 helmet study, was not surprised by the Rowson study's findings. That it is now the third study reporting that helmet design can affect concussion risk, he said, made him a "little more confident" and "hopeful" that helmet technology is "going in the right direction.""Scientific research is a process," Collins said, and he was glad to see the Rowson study "building on his research."
Interestingly, the difference in concussion risk between the two helmets matched almost exactly the estimated difference in concussion risk between the two helmets calculated by the STAR helmet rating system , a test of helmets in a laboratory environment developed by Duma and Rowson, which is designed to measure their effectiveness in reducing the forces that cause concussion. The data obtained from that testing suggested that the Revolution, a 4-STAR helmet introduced in 2000, would result in a 54% reduction in risk of concussion compared to the VSR4, a 1-star helmet employing 20-year-old technology, which was still being worn by as many as 38% of professional players  as recently as 2011.\
"We would never have guessed the risk reduction would have matched so closely," said Duma. "We think that this is excellent validation" of the STAR system, and, in our opinion makes the overall STAR ratings very useful."
[For an updated article on the STAR ratings, click here ].
The reaction to the study from football helmet manufacturers was mixed, ranging from to-be-expected praise from Riddell, whose helmets were the subject of the study (and which, not coincidentally, has been urging college and pro players to switch from the VSR4 to a Riddell helmet with more padding and a larger shell), to caution against interpreting too much into the results and pointing out the study's limitations from a spokesperson for SG Helmets, to sharp criticism by Schutt. (Efforts to obtain comments from the remaining two helmet manufacturers, Rawlings and Xenith, were unsuccessful) Erin Griffin, Senior Communications Manager for Riddell, said the company was "pleased that this study continues to show the value of more advanced helmet technology." She said, however, that Riddell continued to "recommend that parents and players consider multiple data points when choosing a football helmet," including the Virginia Tech STAR rating system, which, she noted, awarded the highest possible, 5-STAR ranking in its latest ratings to two Riddell helmets, the 360 and Revolution Speed.
"We are supportive of credible scientific research like this study that can help educate parents, players and the broader football community about some of their head protection options and about the advancements in football headgear," Griffin said.
Less positive were the comments of Ashley Quintero, National Sales Manager for SG Helmets, a new football helmet manufacturer with a background in designing race car helmets. The adult SG helmet made an impressive debut in 2013 at the top of Virginia Tech's 4-STAR list.
Quintero emphasized the study's limitations and cautioned against painting the results with too broad a brush. "We believe the most informative research is comprehensive and unbiased. In our opinion, the recent Virginia Tech study was not comprehensive, as the study limited its exploration to the products of just one manufacturer."
She expressed concern that, unless those limitations were considered, "there exists the potential for coaches, parents, and athletes to assume these results reflect all football helmets," and she cautioned "consumers against expanding the findings of one study and generalizing that its outcome holds true for all products, " and urged coaches, parents and athletes to make a "well-informed decision based on the advantages and disadvantages of every available product."
Most critical of the new study was Schutt's Chief Executive Officer, Rob Erb. "Stripped of the headline grabbing claims of double-digit concussion reduction, there is little here to get excited about," asserted Erb in a lengthy email to MomsTEAM's Brooke de Lench.
The best that can be said about the published Technical Note, Erb said, based upon what he characterized as a "limited data set," is that it suggests that players who wore large standoff shelled Riddell Revolution helmets were diagnosed with fewer concussions than their counterparts who wore the much smaller standoff VSR helmets. However, even this conclusion, he argued, "would have to be taken with a grain of salt, because the statistical differences can be accounted for by a number of factors not discussed by the authors."
"What is striking is that we continue to give great deference to those that take the most simple and extreme positions when we know that the truth is often complex and less likely to be the subject of a headline," Erb concluded.
[For the full text of Erb's email, dated February 10, 2014, click here ]
Timothy McGuine, a Senior Scientist in the Department of Orthopedics and Rehabilitation at the University of Wisconsin School of Medicine and Public Health, said he viewed the Rowson study as "excellent" and with an "outstanding" roster of authors. "I agree with its finding that current helmet designs are better than those from 6 to 10 years ago," McGuine said.
The findings of the Rowson study appeared at odds with those of his 2013 research paper (McGuine T, Brooks, et al 2013). That paper, which has not yet been subjected to the rigors of peer review required to gain publication in a medical journal, reported that the risk of sustaining a concussion in high school football was not affected by the brand or age of the helmet.
McGuine said the findings of the Rowson study and his paper, however, were not irreconcilable, but likely due to important differences betweenthe two studies in objectives and data collection methods.
First, he said, the Rowson study was a "retrospective study that went back and looked at SRC [sport-related concussions] using impact data (HITS system) and medical records. Their data collection took place over a 5-year range in college players [and] compared the VSR-4 and Revolution models. They had excellent data reporting at the university level with outstanding medical staffs and unlimited access to medical records and imaging."
"On the other hand, our study looked prospectively at helmets brands currently being used in 2012 and 2013, two-thirds of which had been purchased since 2010, and included only a total of 11 old VSR-4 helmets. Our goal was to look at the rate of SRC in helmets available and being purchased now, so school ATC's, coaches and parents would have information they could use to help guide their decision-making processes. These [are] people [who] are not asking if the Riddell Revolution is better than a VSR-4 [which is no longer on the market]. They want to know if one helmet brand, currently available, that may cost $400+ dollars, is better than a helmet costing $200."
McGuine said he agreed that measuring impacts with the HITS sensor arrays provides "a better picture of the actual helmet performance," which his study was not able to provide and hence listed as a limitation. "I would love to use the HITS system to do a study on actual brands/models being used currently by high school players."
In addition, he pointed to the difficulty of collecting data in 50 communities. In contrast to the 1,800 athletes involved in the Rowson study, all of whom were seen the same 8 team doctors, "the kids in our study who were injured did not all see the same medical provider or undergo the exact same diagnostic procedures."
Further, Implementing that level of data collection in 50+ high schools was cost-prohibitive, costing between $1 and 2 million, said McGuine.
\"If someone is willing to give us that level of funding, we would do it. Unfortunately, we could not get any external support for this research, and were limited to using $50,000 of our own money and could only report data that such level of funding would allow."
Nevertheless, McGuine expressed "confidence in our data collection procedures and results, given the variables we could control. The scope of the variables we measured also gives us insight into other factors that may play a role in SRC susceptibility. I see these data as being just as important for high school ATC's coaches and parents," and I don't see those other variables mentioned in [the Rowson study]."
Mike Oliver, Executive Director of the National Operating Committee on Standards for Athletic Equipment (NOCSAE), the non-profit group that sets standards for football helmets, said in an email that NOCSAE was "still reviewing the study and its conclusions." "It is hard to tell at this point whether the conclusion is that the Riddell Revolution helmet model is better than the Riddell VSR 4 model, or whether that conclusion also applies to other helmet brands and models," Oliver said, "because the two helmets are based on different design concepts, with the main difference being that the Revolution model has a larger shell with more padding on the inside.
He noted that "this type of design difference also exists in almost all other brand helmet models introduced since 2000 when the Revolution was first made available," but that, despite the fact that this new design type has replaced the older style helmets over time, "we [are] see[ing] an increase in concussions, which is not consistent with the study findings. So there are lots of questions and information that the study does not address."
"Until the data behind the study is made available for review and analysis, it is very difficult to evaluate the study. Impact and concussion data has been collected by the Riddell/SIMBEX owned HITS system from collegiate players beginning in 2003 through 2013 but the study only evaluated data between 2005 and 2010. Almost all of the original data collected by Virginia Tech in 2003 and 2004 was done in the VSR4 helmet, but was not included in the study. Additionally the data collected at Virginia Tech after 2010 was done with the Revolution helmet and did not involve any VSR 4 helmets, but that data was not included in this study [either]."
Echoing a criticism made by Schutt's Erb, Oliver said, "We also know that SIMBEX filters the impact data using an internal and propriety algorithm that culls out a percentage of the impacts before being used in the various published studies, and the current study does not address how many of those filtered and excluded impacts involved Revolution helmets."
NOCSAE, which has been sharply critical  of the STAR ratings system in the past, has itself been criticized for failing to move more quickly to update its standards to reflect the ability of football helmets to attenuate rotational acceleration, believed by many concussion experts to contribute more to causing concussions than straight-line or linear acceleration. NOCSAE recently announced plans to unveil a new helmet standard in June 2014.
[For an article setting out Brooke de Lench's full interview with NOCSAE's Oliver, click here .]
In the final analysis, one thing seems clear: while the football helmets on the market today and manufactured in the recent past likely reduce concussion risk to some degree better than older helmets utilizing a different design and less padding, there is, and may never be, a helmet design which prevents all concussions, and whether there is an appreciable difference between different brands of helmets being sold today, has yet to be established. In fact, more important, many experts say, than the helmet brand may be helmet fit.  As not every helmet is going to fit every player, selecting a helmet that fits correctly - snugly almost to the point of being uncomfortable - will allow the helmet - whatever the brand - to perform at its best in protecting the player from injury, which includes staying on the player's head and not coming off during play.
If the finding by McGuine and his colleagues at the University of Wisconsin that brand new helmets are not appreciably more protective against concussion than used and properly reconditioned helmets manufactured within the last five or six years is borne out in future studies, the best advice for parents may be, as he says, "not to become alarmed" if their kid is asked to wear a helmet that is three years old, and, likewise, for administrators "not to be worried about purchasing the most expensive and/or newest helmets."
On the other hand, if future studies extend the findings of the Rowson study to show a measurable and statistically significant difference in concussion risk reduction between, not just a new helmet and an old helmet, but between two or more of the new helmets currently on the market, the company with the helmet found to reduce risk the most will likely reap substantial gains in market share in the highly competitive football helmet market, Regardless of whether one helmet is better than another in reducing the risk of concussion, the best path to making football safer from a head injury standpoint is still to take a multi-pronged, all-the-above approach, such as set forth in MomsTEAM's Six Pillars , which, beyond equipping players with properly fitting helmets, includes:
Collins M, Lovell MR, Iverson GL, Ide T, Maroon J: Examining concussion rates and return to play in high school football players wearing newer helmet technology: a three-year prospective cohort study. Neurosurgery 2006;58:275-286
McGuine T, Brooks A, Hetzel S, Rasmussen J, McCrea M. "The Association of the Type of Football Helmet and Mouth Guard With the Incidence of Sport-Related Concussion in High School Football Players." Presentation Paper AOSSM, July 13, 2013.
Rowson S, Duma SM. The Virginia Tech response. Ann Biomed Eng 2012;40:2512-2518 (Letter)
Rowson S, Duma SM, Greenwald RM, Beckwith JG, et al. Can Helmet Design Reduce the Risk of Concussion in Football? J Neurosurg. 2014; 10.3171/2014.1.JNS13916 (published online ahead of print January 31, 2014).
Photo courtesy of Virginia Tech - Wake Forest