"If we’re ever going to make decisions on whether somebody gets to play or not based on the number of hits they’ve taken, we should have a clear scientific understanding of what those hits are doing, and we don’t," Dr. Kutcher said. "There’s a general concept that the types of hits that athletes take during contact sports can’t be good for the brain. The real question is, how bad is it? The underappreciated aspect of this is how individual that answer is. If you took 100 players and gave them the same type and number of exposures over a lifetime, you’re going to get 100 different results."
Several planned studies sponsored by the NFL, the Department of Defense, and the National Institutes of Health will evaluate new football helmet designs and test accelerometers inside them to measure the frequency and force of hits in relation to the players’ neurologic status. Other studies are proposing to compare a group of age- and position-matched former NFL players with players who played at the collegiate level and control subjects who did not play sports, according to Dr. Batjer.
In another study, Dr. Kutcher said that he and investigators from the University of North Carolina at Chapel Hill and the University of California, Los Angeles, will track the longitudinal neurologic status of players of both genders in sports with and without helmets (using accelerometer-instrumented mouth guards) throughout their career and afterward against control subjects.
Doug Brunk contributed to this report.