NFL players were diagnosed with more concussions in 2017 than in any season since the league began sharing the data in 2012, according information released Friday afternoon.
There were 281 reported concussions during the preseason and regular season, including practices. The previous high was 275 in 2015.
Speaking Friday on a conference call, league executives acknowledged concern about the numbers and attributed most of the jump to a spike in preseason practice concussions.
"Certainly, we're disappointed that the concussion numbers are up," said Dr. Allen Sills, the NFL's chief medical officer. "It is something which challenges us now to roll up our sleeves and work hard to see that number go down. ... We take this is a challenge, because we're not going to be satisfied until we drive that number much lower."
In 2017, teams reported a total of 56 concussions during practices; that number was 32 in 2016 and averaged 44 between 2012 and 2015. Of the 56 practice concussions, 45 occurred during the preseason.
According to Sills, the league is analyzing details such as the types of drills that players were participating in when concussed. It will prepare and transmit individualized reports for each team, likely by the beginning of March. It's possible they could lead to new guidelines and policies for next season, especially during training camp.
"That drove our attention after a couple of years where those preseason practice concussions decreased," said Jeff Miller, the NFL's executive vice president of health and safety initiatives. "This is an important aspect of the work we'll be doing between now and the combine, and not just with the medical experts, but obviously how practices are run at the club level. [That] is something under the control of the coaches, the general managers and others who are on site."
Concussions during games also rose, from 211 in 2016 to 225 in 2017. Some of that increase could be attributed to a bump in self-reporting by players. According to an analysis by IQVIA, the league's injury data partner, 28 percent of concussion evaluations during games were prompted by a player reporting his own symptoms. That was up from 18.4 percent in 2016. But Christina DeFilippo Mack, senior director of epidemiology at IQVIA, said she couldn't yet say how many of the diagnosed concussions -- as opposed to the assessments -- started with a self-report.
Meanwhile, the league's data also showed that for the first time since at least 2014, injury rates were higher on Thursday night games than they were during regular-season games. There were an average of 6.9 injuries per game on Thursday nights and 6.3 on other days. IQVIA defined an injury as one that caused a player to miss time, either in that game or subsequent ones.
The league has defended its Thursday night schedule, which puts players back on the field with three days' less rest than normal, by noting that they produced no difference in injury rates.
Friday, Sills said: "Assessing the overall health and safety impact of the game is a lot more complex than just a simple injury rate."
IQVIA's DeFilippo Mack said the one-year flip in injury rates was statistically insignificant, while Sills said there are many other factors involved in evaluating Thursday night games than injury rates.
"It would be somewhat naïve and superficial of us to say that because the number went up or down that Thursday night is safer or more dangerous," he said.
Also, injuries to the two primary knee ligaments in 2017 were mostly unchanged from 2016. There were 54 torn ACLs in 2017 and 56 in 2016. There also 147 MCL tears, up slightly from 143 in 2016.