NFL Chief Medical Officer Dr. Allen Sills said the league "did a targeted intervention" with seven teams in regard to concussions.
Sills said, per Dan Graziano of ESPN.com, those seven teams were identified to have more preseason concussions than their counterparts during the 2017 campaign. As a result, the league met with the football operations staffs of each team to discuss practice drills and types of helmets that may have contributed to the higher numbers.
"In six of those seven clubs, the numbers did go down," Sills said. "Those seven clubs had 23 practice concussions as a whole in 2017, down to nine in 2018."
The decrease in concussions for those six teams mirrors a league-wide trend, as the NFL noted preseason concussions declined from 91 last year to 79 this year.
"We are cautiously optimistic about that result," Sills said. "We are pleased to see that number go down, but we still have a lot of work to do."
The league instituted a number of changes in an effort to make the game safer, including the distribution of flyers to players that rank helmets on a green-to-red scale (green being the safest and red the most dangerous). Jeff Miller, the NFL's senior vice president of health and safety policy, said just 40 players were wearing red helmets as of Week 3 this year compared to 230 last year, per Graziano.
This year, new players were not allowed to wear red helmets, which will be banned for all players in 2019.
On the heels of a rule change, the league also said there were zero preseason concussions on kickoffs. Under the new rule, players on the kicking team have to remain stationary until the ball is kicked to prevent running starts and harder collisions.
Elsewhere, the NFL is penalizing contact initiated by lowering the helmet and has heightened its focus on roughing the passer.
While there has been plenty of angst around the league from players, coaches and fans regarding the additional enforcement of the rule that states a defender can't use most or all of his body weight while landing on a quarterback, the rules are designed with player safety in mind.
If the preseason concussion numbers are any indication, a positive trend has started in the reduction of head injuries.