NEW YORK - The number of concussions in the NFL dropped 13 percent from 2012 to 2013, according to data the league released Thursday and touted as a result of its efforts to better protect players' heads.
Using information collected from team doctors during preseason and regular-season practices and games, the NFL also said there was a 23 percent decrease over the past two seasons in the number of concussions caused by helmet-to-helmet contact.
Speaking at a pre-Super Bowl news conference, Jeff Miller, the NFL's senior VP of health and safety policy, called the data "positive numbers from our perspective; positive trends."
"Our perspective is that rules changes, culture change, the enforcement of the rules and the elimination, over time, of dangerous techniques is leading to a decrease in concussions.
"Now all of that said, we're talking about a small sample size of only a couple of years," Miller said.
"This is an ongoing and important culture-change event, and so we're going to continue to analyze it and I think that there's room for continued growth," he added. "So we're pleased with the data, unquestionably, as it relates to concussion, but there's still more to do."
Some players have expressed concern that the NFL's emphasis on decreasing hits to the head could lead to more low hits and more knee injuries. But Miller said the injury statistics for the past three years - the only seasons for which he provided data Thursday - show there has not been an overall increase in damaged knee ligaments.
Another finding about all injuries that cause a player to miss a game or practice, according to Miller: "Thursday night games don't pose a more significant risk of injury to the players, at least as relates to the objective data that we've collected" about that day of the week, as compared to games on Sundays or Mondays.
Concussions rose nearly 4 percent from 2011 to 2012 - 252 to 261 - before lowering to 228 this past season.