The college bowls of New Year’s Day are behind us, and many football fans are already looking forward to next month’s Super Bowl. But they’re also talking more about the traumatic head injuries that plague football players, which scientists and clinicians still don’t understand fully.
One Stanford team is measuring the physical forces that an athlete’s head undergoes in a much more detailed way than in past studies, using a specially-outfitted mouthguard that we wrote about last year. Just before Christmas, Stanford bioengineer David Camarillo, PhD, and his team published a paper in the Annals of Biomedical Engineering that provides a much more complete picture of head injuries among athletes.
Helmets used in football and other sports are only evaluated on how well they protect in three directions of movement: front/back, up/down, and left/right. But, as a press release from the university notes, researchers suspect that rotational accelerations (roll, pitch, yaw) play an important role in serious injuries.
The team customized a commercially available mouthguard to measure movement in all six directions, and they recorded 500 impacts on Stanford football players, local boxers and mixed martial arts athletes. Two of the impacts resulted in concussions. The researchers analyzed the impacts and found that using six degree-of-freedom data proved to be more predictive of injuries than the current three degree-of-freedom standard. They also found that one particular part of the brain is more likely involved in concussion injuries. The release details these findings:
The current work... has helped identify a brain structure that bears closer scrutiny for its potential role in concussion symptoms. While the two concussion impacts inflicted very different magnitude and directional forces on the head, computer models indicated that they both put strain on a particular part of the brain, the corpus callosum. Previous concussion studies have identified the corpus callosum as a potential injury site.
"One of the things the corpus callosum does is manage depth perception and visual judgment by communicating and integrating information from each eye across the left and right hemisphere of the brain," said lead author Fidel Hernandez, a mechanical engineering graduate student in Camarillo's lab. "If your eyes can't communicate, your ability to perceive objects in three dimensions may be impaired and you may feel out of balance, which is a classic concussion symptom."
At the beginning of this year, a new law went into effect in California limiting the time high school football players’ full-contact practice time to just two 90 minute sessions per week; the new law also bans out-of-season full-contact practice. Texas has had a similar law on the books since 2013. The laws indicate the growing concern over head injuries, and more accurate information from studies like Camarillo's can help coaches and parents decide when a player needs to step off the field.
Beyond influencing possible changes to industry standards, another possible implications for Camarillo’s research is that it will allow coaches to remotely monitor impact forces that players undergo. Many players under-report impact injuries, something that complicates understanding the phenomena. Accurate measurements can help clarify the picture.
Previously: Mouthguard technology by Stanford bioengineers could improve concussion measurement, Stanford undergrad studies cellular effects of concussions, Kids and concussions: What to keep in mind, Developing a computer model to better diagnose brain damage, concussions and Study suggests football-related concussions caused by series of hits, not a single blow.
Photo by Jacoplane