How often do concussions occur in football for kids and young adults?

In any one high school football season of 10 games, assuming 40 athletes participated; four players will have a concussion.  Concussions in football occur frequently, but when do they usually happen?  A slight majority of concussions happened during youth football games, but most concussions at the high school and college levels occurred during practice, found a study published online today JAMA Pediatrics.

The study compared concussion rate across youth football (7 to 14 years old), high school football, and college football and game injuries versus practice injuries.  The authors also showed essentially no concussions in midget football (5 to 7 year olds).  The study also showed that athletes were more liable to get injured in games than practice.

Using data collected from three (youth, secondary, and college) large injury surveillance systems, the study found that during the 2012 and 2013 seasons there were 1,198 concussions reported with 141 (about 12 percent) of them in youth athletes, 795 (about 66 percent) in high school athletes and 262 (about 22 percent) in college athletes.

The results also showed about 54 percent of concussions occurred during youth football games, but in high school and college most concussions (about 58 percent and about 58 percent, respectively) happened during practice. The study's authors noted, "Concussions during practice might be mitigated and should prompt an evaluation of technique and head impact exposure"

This is the first study to compare concussion rates across age groups in such detail with concussions going up as players got older, but going down some at the college level.  But this rigorous study of when concussions occur forgot to add why concussions occur more as players get older: the weights of the players and the way the brain grows.

When I played high school football in the 1960s, I was the heaviest player on my team at 198 lbs. or so. Now even the smallest high school lines are full of players over 200 lbs. And, since there is no weight limit in high school or college football, the amount of force when two 250 lbs. of players hits each other is five times the force of two 100 lbs players hitting each other. This doesn't even take into account the speed they are going and, in general, two 18 year-olds can run much faster than two 12 year-olds.

Brains keep growing until around our early 20s when they fill up the skull, but skulls are 95 percent of adult size by age 10 at the latest. So as one goes from youth football to high school football to college football, the chance that a skull impact will actually hit the brain itself increases as there is less empty room between the skull and the brain.

But why did concussions go down in college ball? I am not sure, but in general, college players are better equipped, better trained and better athletes than younger players so injuries from mistakes may be less. I was a starter in high school, but even on a very bad college team, I was mainly a substitute.  A college player has spent more time building up their bodies, especially the neck muscles, and that will help some, but the reason for the decrease in injuries is not clear.  By the way, the number of actual serious concussions in college ball per a game basis is still about 4 per a 10 game season since colleges use many more people in each game than high schools do.

Why are more serious injuries more likely to occur in games than practice?  At first glance, one would think the opposite.  Practice sessions are often twice as long as games in actual playing time, and involve everyone, not just the best players.  But many coaches avoid players hitting other players and have them do the hitting against machines.  Also the player most likely to get hit hard, the quarterback, is completely off limits to touch in practice.

Think of the dilemma of concussions in football this way: if your car is hit by a brand new Mack truck that is speeding, you are more likely to be seriously injured than if hit by an old VW Beetle that can barely get to the speed limit.  To avoid concussion, get hit by a younger, lighter player.

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