Impact Sensors: A Missing Piece of Head Injury Programs

In believing that impact sensors could play a role in the early identification of concussion, I have had good company in the sports medicine and scientific communities.  Numerous studies have shown that one of the biggest hurdles to appropriate clinical management of sports concussion is identifying athletes who should be removed from play for initial screening on the sports sideline.  Many sports concussions go undetected because athletes don’t recognize that they have symptoms of concussion, are reluctant and/or refuse to self-report such symptoms, or because of the less-than-perfect observational skills of sideline management in spotting signs of concussion in athletes.  Early identification is critical because, in most cases, athletes immediately removed from contact or collision sports after suffering a concussion will fully recover fairly quickly (7 to 10 days, longer for children), while athletes who continue playing after concussion, according to recent studies, are at much greater risk of a longer recovery.

One way to address the problem of chronic under-reporting and increase the chances a concussion will be identified early on the sports sideline, say some leading experts, is to rely less on athletes to remove themselves from games or practices by reporting concussion symptoms, or on game officials and sideline observers to observe signs of concussion, but to use impact sensors as essentially another set of eyes to alert sideline personnel to heavy hits that might cause a concussion.  “Although a [sensor] system may not be able to accurately predict injury,” notes University of Michigan and Michigan Neurosport neurologist Jeffrey Kutcher, “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.”  A 2017 study in the Journal of Athletic Training agreed, concluding that “impact sensors may provide critical real-time data to monitor players,” and that “viewing an athlete’s head-impact data may provide context for the clinician working on the sidelines.”

Another benefit of using impact sensors, says Richard M. Greenwald of the Thayer School of Engineering at Dartmouth College and Co-Founder and President of Simbex, the maker of the HITS sensor system widely used by concussion and biomechanical researchers, is that they not only “facilitate the early recognition and management of brain injury in helmeted sports but permit early intervention, potentially in advance of an injury, rather than simply as a management tool postinjury, by identifying high magnitude impacts which may cause concussions, and athletes sustaining high number and/or high magnitude head impacts who may be more prone to concussions.”

Sensors have also shown value as a teaching and behavior-modification tool for athletes in order to reduce the total amount of brain trauma athletes suffered in contact and collision sports such as football from repeated subconcussive blows.  If a player is observed repeatedly sustaining higher magnitude impacts, especially to the crown of his head – which studies suggest are most worrisome from a brain trauma standpoint – coaches can work with the athlete on adjusting his technique.  As one youth football coach recently told a newspaper in Washington State, “Concussion prevention starts with teaching.  These products will help our coaches know when a kid has a problem. It is a safety measure and a teaching tool.” 

Using impact sensors as a teaching tool has already been happening in high school football. After Purdue researchers found in a landmark 2010 study that high school football linemen who sustained a high number of high-impact, sub-concussive hits over the course of a season suffered impairment of their visual memory, impairment which persisted beyond the season. In an interview with PBS’s Frontline, Tom Talavage, the lead author of the Purdue study, estimated that least 50 percent of the high impact hits high school football linemen and linebackers were sustaining were due to poor technique.  The information led at least one player to change his blocking technique, leading to a drastic reduction in the number of blows sustained to the top front of his head and a moderate reduction in the total number of helmet hits.  After the second season, Talavage reported that the player’s “neurocognitive testing never detected any deficits, and from a [brain] imaging perspective we saw substantially less change in [abnormal brain] activity. “