Mouth guards used to analyse head concussions

It's no secret that concussions are endemic in American football at every level, from pewees to the pros, but little is known about the hits that cause them. Stanford University is searching for answers by meticulously gathering data on every impact their football players sustain. The study is only in it's second year, but they've already made some interesting discoveries.

David Camarillo is a bio-engineer at Stanford and a lead researcher on the project. He says “injury research is a tough thing to do because you usually see it only after it happens.” To see brain trauma in real time, Camarillo and his team have outfitted the football team with mouth guards that measure the physics of every hit. At practices, they use ultra-high-definition, slow-motion cameras to observe those collisions more closely and look for ways to prevent them...

The team wears the mouth guards at all games and practices so that researchers can generate a comprehensive database of every impact they sustain. The sensors measure linear and angular acceleration—how fast the head is moving in one direction and rotating. The sensors may sound high tech, but actually, you might have some in your pocket right now. They are the same ones used in the iPhone 5.

Camarillo says the mouth guards have already captured some startlingly hard hits, like the one that ended the season for a wide receiver. That collision registered an acceleration of 150 Gs, that's 150 times the acceleration gravity. “Pretty serious business,” he says, “a standard boxing punch is probably between 10-20 Gs. 

That's just acceleration in one direction. The player's head was also spinning at 2000 degrees per second—which means his head would have rotated five and a half times in one second if it weren't anchored to the neck. While it has long been suspected that this kind of angular acceleration plays a role in concussions, Camarillo says no one has gathered data on it. What's more disturbing is that angular acceleration has been completely ignored when it comes to football safety measures. 

Further details in the Quest column at KQED's website.