A year ago, I interviewed Purdue University director of athletic training education Larry Leverenz, PhD, ATC at the Indiana Athletic Trainers' Association's annual meeting. We talked about his ongoing study on the effect of repeated head impacts on high school football players.
Recalling a meeting with colleagues, early in 2010, when they realized that non-concussed players were suffering measurable brain damage, too, he said, "There was dead silence in the room."
Leverenz and his colleagues in West Lafayette are now in their third year of the study and have expanded its scope from Lafayette Jefferson High School to West Lafayette High School and from football to girls soccer.
This year at the IATA annual meeting, there were numerous speakers, one of them, Leverenz. When he took the podium on Monday morning last week, the room was full with more than 300 professional and student athletic trainers, by far the best-attended presentation of the conference. In anticipation of what was to be said, there was dead silence in the room.
For good reason.
Those in attendance were waiting to hear how many hits to the head are too many.
The Purdue researchers are using the ImPACT computerized neurospsychological test, functional magnetic resonance imaging (fMRI), Riddell's HITS (head impact telemetry system)/Revolution helmet, and soccer head bands equipped with force sensors. With those high tech tools, they are gathering data regarding the effect of quantity and quality of head collisions.
The numbers don't lie.
Football players who suffered neither concussion nor measurable brain damage experienced an average of 51.8 hits to their heads per week.
The football players who suffered a concussion experienced 60.7 hits per week, with most of the concussions being caused by a blow to the side of the head. Players and coaches refer to such a hit as getting "earholed."
Those who hadn't been concussed but registered decreases in brain function averaged a whopping 126.9 helmet hits per week. These individuals were typically linemen and most of the hits were to the front and top of the helmet. The impaired scores were registered in the visual memory (versus verbal memory) section of the ImPACT test. And fMRI results correlated perfectly with the ImPACT scores.
Using the HITS software, Leverenz found that players who suffered no impairment, "control the contact they initiate, exert some control over how they are hit, avoid leading with their head, and avoid unnecessary collisions."
By contrast, those who weren't concussed but still exhibited impairment, "tended to be reckless in tackling -- or overmatched, lead with their helmet, be hit when in poor position, and accumulate many collisions."
In short, the fewer collisions, the better.
As for soccer, Leverenz started this year with the hypothesis that heading the ball is not dangerous. Based on the preliminary data he's reviewed, though, Leverenz warned, "We're not going to be able to say that."
John Doherty is a certified athletic trainer and licensed physical therapist. This column solely reflects his opinion. Reach him at firstname.lastname@example.org.