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.