Children are Not Miniature Adults when it comes to Brain Injury[1]
Children between ages 9 and 14 make up the largest group of football players in the country, larger in total numbers than high school, college and professional players. Until a recent study by the Virginia Tech Helmet Lab, the research regarding brain injuries caused on football fields largely focused on players in high school, college and pro ranks.
The recent Virginia Tech study, released in the January issue of the Annals of Biomechanical Engineering has corroborated the long held anecdotal belief that youth football players are at greater risk for concussion related injuries than older players.
It has been theorized that the anatomical differences between adults and children accounted for the increased risk of injury to children in football games despite the fact that the head accelerations leading to concussion in youth football are lower than those that typically cause injury to older players.
These anatomical differences include:
- The fatty myelin sheaths that help protect brain cells have not fully developed in children.
- Children usually have heads which are bigger relative to their bodies and less neck musculature to help support the head upon an impact.
The study followed youth football teams in Virginia, North Carolina and Rhode Island. More than 100 players on 6 teams wore helmets containing sensors to measure linear and rotational forces during 4 seasons worth of practices and games.
Thousands of impacts were analyzed. Concussions were diagnosed by clinicians at the site of the events and neuropsychological testing was performed of the kids before and after every season to measure the potential cognitive changes.
The study concluded that youth players are on average more susceptible to concussion at lower levels of acceleration than high school and college players are. For players in high school and college and the pro ranks, to cause a concussion requires the head to be accelerated in a linear fashion at 102 g’s while average impact causing concussion to children was only 62 g’s. A similar mathematical difference was found with rotational acceleration.
What is a g??
We use “G force” to measure acceleration due to gravity. Acceleration is the rate of change in velocity with time.
- At 0 g – we feel weightless, like we are floating in space
- At 1 g – everything feels normal
- At 2 g – we feel twice as heavy.
- A fun roller coaster ride might exert 3-4 g’s of acceleration for brief moments
- Fighter pilots can experience accelerations up to 8 g for brief periods of time
- 60 g’s of acceleration is equivalent to what the human body feels in a car crash at 30 mph with an air bag deployment.
So, when a child is involved in a fall, a car crash or a sports collision, a child’s brain is affected at much lower levels of force that what has been found in adults.
[1] Steve Rowson is an associate professor of biomechanical engineering and mechanics and the director of the Virginia Tech Helmet Lab. He was quoted in an article authored by Eleanor Nelson of the Virginia Polytechnic Institute and State University as saying, “Children aren’t just scaled-down adults: Differences in anatomy and physiology, like head-neck proportions and brain development, contribute to differences in tolerance to head impact.”
