Certainly there is great sensitivity to the issue.

I can give you 100 dentists who say they've got the best method for reducing concussions. Many times I've had them in my office. One brought me a box of cookies. My response to that person and to 20 others is that I'm intrigued, but it's your job to prove to me your idea does what you say it does.

There's a rush to judgment that his death was related to his obesity, and that's an open-ended question. We're trying to answer the questions: Is there obesity in the NFL? And if there is obesity, are the players at more or less or the same risk as their counterparts in the real world? Those are questions we have to answer.

It's something that has not been looked at as carefully as it could have been, in terms of regarding shoes as a protective device. But one year's worth of data does not make it a problem. There can be anomalies.

The most dramatic difference was evident on tests measuring reaction time and speed: NFL athletes demonstrated rapid return to expected levels of functioning, while the high school group lagged behind.

We still feel we need to be able to look at the player population more to see if it makes sense to perform echocardiograms on everyone. People get emotional and think that we are in a dark closet conspiring how not to do the right things for the players. While we have a responsibility as physicians to do as much as we can to prevent, we also have to be careful not to come to premature conclusions since someone's livelihood is at risk.