KISSIMMEE, Fla. — Rebecca Morgan squared her feet, bent her knees, raised her hands and tried to connect with her inner linebacker. Beside her, two dozen other mothers did the same as they listened to Mike Haynes, a former N.F.L. defensive lineman, teach them how to tackle safely.

The women were taking part in a Moms Clinic, one of hundreds conducted nationwide by USA Football, a nonprofit group that was started by the N.F.L. 12 years ago and is at the forefront of efforts to combat the toll that concussions have taken on the sport.

Through USA Football, the N.F.L. has targeted mothers, many of whom decide which sports their children play but have not competed in football themselves, to reassure them that the game can be safe.