The MomsTEAM staff and I are still digging into the Institute of Medicine and National Research Council's three-hundred-some-odd page report on sports-related concussions in youth sports,[1] but one thing jumped out at me at my first pass: When I did a search in the report for a discussion of impact monitoring devices (a/k/a hit sensors), I found only one brief mention of sensors in the committee's recommendation that the Centers for Disease Control fund large scale data collection efforts for research purposes, including data from impact sensors.
Conspicuous by its absence from the report was any mention of the practical applications for such technology, especially but not limited to helping to identify athletes who may have suffered a concussion so they can be evaluated for possible concussion on the sports sideline.
I know firsthand from working with high school football players while producing "The Smartest Team," that impact sensors hold enormous promise, most significantly as a technological 'end around' the "culture of resistance" to self-reporting concussion symptoms, which the IOM/NRC report correctly recognizes as perhaps the single biggest obstacle to improving concussion safety in contact and collision sports.
But I found the omission especially glaring and surprising given that a number of leading concussion researchers, including the University of Michigan and Michigan Neurosport's Jeffrey Kutcher [2] and Steve Broglio, [3] have both written recently about the benefits of real time impact monitoring, not just for research, where they have been used in gathering biomechanical data for about a decade, but on the sports sideline.
Writing about head impact sensors in a study about emerging technologies in concussion identification and management in the March 2013 issue of the British Journal of Sports Medicine,[2] Dr. Kutcher, a neurologist specializing in the treatment of sports-related concussions and the co-author of the updated, evidence-based concussion management guidelines issued by the American Academy of Neurology,[4] viewed the "development of easily deployable sport equipment-based accelerometer systems" as "providing potentially useful, clinical information" in at least two ways.
First, Kutcher said, impact sensors have utility in monitoring impacts during the course of an athletic event for the purpose of screening for potential injury. While acknowledging that " an on-board accelerometer system may not be able to accurately predict injury," Kutcher said, "it may have utility as a screening device by alerting sideline personnel of an impact that has occurred above a predetermined magnitude that triggers either observation or clinical evaluation of an athlete."
Second, Kutcher also saw a potential clinical benefit for real time impact monitoring systems, one which "stems not from the idea of monitoring impacts for the presence of an acute injury-generating hit, but from the potential advantage of accurately cataloguing the number of hits and post-impact head acceleration being experienced by an athlete over time."
"Some have suggested that the idea of a 'hit count' that is kept for athletes over the course of a game, practice, week, month, season or career," he writes. Kutcher recognized that the "concept is fairly new and, as yet does not have published data to suggest that any particular level or number of hits has significant clinical meaning for any particular sport or position." On this point, the IOM/NRC report essentially agreed, stating that "implementing a specific threshold for the number of impacts or the magnitude of impacts per week or per season was without scientific basis." Nonetheless, he said that "individual athletes may feel there is a benefit to having an estimate of forces their brain experiences over time."
For his part, Dr. Broglio is also on record as seeing merit in the use of impact sensors in facilitating the identification of concussed athletes. While he acknowledged, as do I, that sensors are currently beyond the reach of most football programs, he, like I, saw a day in the not too distant future when use of such instrumentation would be "both practical and feasible."
In case you don't know about Steve, he is, along with Kevin Guskiewicz at the University of North Carolina, and Steve Rowson and Stephan Dumas at Virginia Tech, one of the leading experts on the use of accelerometers in football helmets in biomechanical studies, so he knows whereof he speaks (or to paraphrase the old John Houseman ad for Smith Barney, When Broglio talks, people should listen.)
Teaching tool
Speaking of Guskiewicz, in a recent article on SI.com he pointed to a third practical use for impact sensors outside of the research arena: to help coaches and other personnel identify athletes who are sustaining a high number of high force impacts, especially to the top front of their helmets that appear to be the most worrisome from a brain trauma standpoint, as a result of poor tackling or blocking technique.
Since emerging research suggests that repetitive subconcussive impacts may actually have more of a deleterious long-term effect on the brain than those blows that result in concussion, why didn't the IOM/NRC report recommend use of data from impact sensors by football coaches to reduce total brain trauma by modifying behavior, as Guskiewicz has been doing at UNC for years? "If a player is observed repeatedly sustaining larger impacts to the crown of his head," he told SI, "coaches will work with him on adjusting his technique."
Using impact sensors as a teaching tool isn't just happening at the college level. It is happening in high school football, too. After Purdue researchers[5] found that high school football linemen who sustained a high number of high impact sub-concussive hits over the course of a season were the ones suffering impairment of their visual memory, the information led at least one player to change his blocking technique.
As Tom Talavage, the lead author of the Purdue study, told Frontline in a 2011 interview, he thought at least 50 percent of the high impact hits linemen and linebackers were sustaining were due to poor technique. "Some of the players that we have on our team have not very good technique, to be quite honest. And what you'll find is, they will launch into a play, and they will lead with their helmet. Other players will more correctly keep their head up, try to get their arms up as a blocking technique, or when they're rushing, they will try to get their arms up as a means to push the offensive lineman out of the way. Those technique differences lead to a very large difference in the total number of blows experienced and where those blows are experienced on the head."
Talavage said that when one of the offensive lineman who was found to have been functionally impaired after sustaining a high number of subconcussive blows, impairment that persisted beyond the season, decided to change his technique, he experienced a drastic reduction in the number of blows he experienced to the top front of his head and a moderate reduction in the total number of blows.
The result was that, after the second season, "his neurocognitive testing never detected any deficits, and from an imaging perspective we saw substantially less change in his fMRI activity. There's still some, because he's still getting hit, but his technique changed the distribution."
Research suggests that the cumulative effect of subconcussive impacts increases the risk of long-term neurodegenerative diseases such as CTE, PD, AD, MCI and ALS. While researchers continue to look for the concussion "holy grail" in the form of specific impact thresholds above which concussions are highly likely and/or the number of impacts or the magnitude of impacts per week or per season that substantially increase the risk of long term brain injury, why not use technology available right now to do what we can to reduce total brain trauma by using impact data to identify kids who need more coaching so they can learn how to tackle and block without using their helmets?
Red herrings
Given what so many respected scientists are saying about the use of impact sensors, why, again, is there no mention in the IOM/NRC report of any of these uses?
Was it because the committee was under the impression that the impact sensor systems that have come on the market in recent years are intended to diagnose concussions. Was it out of concern that equipping players with sensors would provide a false sense of security and foster a belief that if the sensor didn't go off, the player didn't suffer a concussion?
The fact is that sensors are not intended to be diagnostic, or to replace sideline observers, game officials, coaches, and teammates, who, if they observe an athlete exhibiting signs of concussion, can trigger a sideline screening for concussion using one or more assessment tools (eg. SCAT3, King-Devick, Maddocks questions). They are simply intended to be another tool in the concussion toolbox or, put another way, another set of eyes. Like those assessment tools, the fact that a sensor triggers an alert - or fails to set off an alert - is not intended to rule an athlete in or out of action or in any way diagnose concussion
The biggest challenge, of course, to widespread deployment of sensors now is their cost. The NFL and college football programs may be able to afford the technology, but coming up with the money to equip teams at the youth and high school level will require creative funding solutions, at least until the cost per player comes down, as it inevitably will over time.
The Institute of Medicine and National Research Council could have given impact sensors a big boost had the report at least discussed their use. Unfortunately, the lack of any such discussion will just end up making it that much more difficult to get the message out about the benefits of real-time impact monitoring, and places an additional obstacle in the path to their use.
It was a barrier that they simply didn't need to raise.
1. Institute of Medicine (IOM) and National Research Council (NRC). 2013.Sports-related concussions in youth: Improving the science, changing the culture. Washington, DC: The National Academies Press.
2. Kutcher J, McCrory, Davis G, et al. What evidence exists for new strategies or technologies in the diagnosis of sports concussion and assessment of recovery?Br J Sports Med2013;47:299-303.
3. 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 Med2013;20(10). DOI:10.1177/036354651302458 (epub September 3, 2013).
4. Giza C, Kutcher J, Ashwal S, et al. Summary of evidence-based guideline update: Evaluation and management of concussion in sports: Report of the Guideline Development Subcommittee of the American Academy of Neurologists. Neurology 2013;DOI:10.1212/WNL.0b013e31828d57dd (published online ahead of print March 18, 2013).
5. 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)
Brooke de Lench is Founder and Publisher of MomsTEAM.com, author of Home Team Advantage: The Critical Role of Mothers in Youth Sports, and the producer/director of the PBS documentary, "The Smartest Team: Making High School Football Safer."
