Youth football players may be much more likely to suffer concussions in games than during practice.
The new analysis in the Journal of Pediatrics finds older players have a much higher risk of concussion than younger players.
Researchers looked at nearly 500 players aged 8 to 12 in four youth tackle-football leagues.
Of the 20 players who suffered concussions, 18 occurred during games and two during practice. Players ages 11 and 12 were nearly three times more likely to suffer the brain injury than younger players.