A 2014 study (Rowson S, Duma SM, et al 2014) reporting that football helmet design can reduce concussion risk has prompted criticism from some of the football helmet manufacturers whose helmets were not involved in the study.
In the interest of accurate and complete reporting on the study, set out below is the full text of an email dated February 10, 2014 from Rob Erb, Chief Executive Officer of Schutt Helmets, to me:
[February 17, 2014 update: Asked for comment on Erb's email, lead co-author Stefan Duma, took issue with his statement that the article in the Journal of Neurology was not a peer-reviewed study: "The paper was fully peer reviewed, not an FYI as [Erb] claims," said Duma. "The term ‘technical note' is just how that article categorizes papers according to word-count. This is a shorter, simpler paper, and thus is called a technical note. It was reviewed, and we had to respond to reviewers' comments before the paper was accepted. Also, it should be noted that there are 15 co-authors, which by itself is quite a bit of peer review."]
Please use this.
While I appreciate your offer to revise my earlier statement, Brooke, it would be misleading to suggest that the recent data supports the proposition that one helmet reduces the incidence of concussion more than another. There is a need for an abundance of caution in this respect.
Stripped of the headline grabbing claims of double-digit concussion reduction, there is little here to get excited about. The best that can be said about the published Technical Note, based upon the 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 would have to be taken with a grain of salt. The statistical differences can be accounted for by a number of factors not discussed by the authors.
It should be recalled in 2006 a group of Riddell researchers reached the conclusion the Revolution reduced concussion by 31%. [Collins, Lovell MR, et al 2006] The work was widely criticized and principle authors recanted the claims saying they were blown out of proportion and ignored their statements that much more work was needed prior to making such a claim. In 2012 some of the same authors that are on the paper your are inquiring about came to the conclusion that the Revolution reduced concussion by 85%. [Rowson S, Duma. 2012] Now the number seems to be 46% even though there were 37 concussions logged in the revolution compared to 27 logged in the VSR. I understand the claim is when normalized for the number of impacts the Revolution looks better, but I wonder if those 37 guys in the revolution at the time of concussion feel that way?
For example, why is the data not separated out by position? You recall that even before taking into account helmet models the Revolution helmet has a large, standoff shell (distance from skull to exterior). We can assume that the larger sized helmets were primarily worn by lineman because of the weight and shape of the shell, which was thought to limit the vision of the player. As a consequence, few of the skill position athletes traded out of the VSR in favor of the Revolution at least at the beginning.
The research supporting the proposition that skill position players are more likely to be diagnosed with a concussion is legion. Wouldn't this alone explain the difference in frequency from 37 player to 27?
And what about the data collection system itself? The authors are not suggesting that the helmet sensors are flawless. Indeed, about 15% of the data is excluded from consideration because of some sort of collection failure, such as the sensor not being secured properly to the head. Were some of these frontal impacts an area known to be difficult for the on field data collections system to capture correctly? If so they would not have been counted because the data would have been thrown out by the Algorithm used, that has never been made public or subject to peer review. Did they tell us how many concussions were missed because there was a data collection limitiation?
And what about the changes in concussion diagnosis during the time period? Many of your articles point to the fact that he definition and understanding of concussive injury is continuing to evolve. The vast majority of doctors will openly acknowledge that "concussion" is a term used as a catch-all for an amalgamation of symptoms, e.g., headache, restlessness, sensitivity to light, difficulty in concentrating, etc. After spending millions of dollars and years of dedicated research, the epidemiology and etiology of concussive injury remains unknown.
What's more, a player can suffer a concussion without being hit in the head. So, why would anyone believe that the addition of a few ounces of vinyl nitrile foam suddenly solves the problem?
As it pertains to football, concussive injuries are thought to be the result of a myriad of factors, including the athlete's prior medical history, genetics, physical characteristics, such as neck girth, position played, age, environment, training, coaching, officiating, temperature, hydration, playing surface, etc., etc.
The time period of data collection is yet another factor. Clearly we should not ignore all the work of the CDC on the Heads Up football initiative; the education of players, trainers, coaches, and officials; and media, such as MomsTeam, in reducing the intensity and number of full contact drills and the like. Doesn't this account for anything?
What would be of greater interest would be to learn how the Speed fared against the Revolution. This seems much more relevant, inasmuch as both have large, standoff shells, that is, recent helmets against recent helmets. And if those 3 star Revolution helmets drop concussion by nearly 50% then with the widespread use of 4 and 5 star offerings the topic of talk on concussions should be they are disappearing. Of course the fact that some of the authors have a financial interest or dependency on Riddell, the star rating system or the NFL might be another avenue for an investigative report to consider.
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.
Finally, perhaps you can assist your readers by helping them understand the distinction between a peer reviewed "study" and the publication of a "technical note." The latter being more akin to giving the academic community a "FYI," and the former requiring some serious academic rigor, including the author's conclusion and a specific recommendation for further action.
Sent from my iPhone
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
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).