Guest blog by Sarah D. Sparks of Inside School Research
Remember that old grade school science experiment in which students chased the positive end of a magnet around the table with the positive end of another magnet, using the repulsive force to push the first magnet away? One researcher is using the grown-up version of that magnet experiment to try to keep football players safer from concussions.
In a presentation at the Society for Neuroscience meeting here, Raymond J. Colello, an associate professor in anatomy and neurobiology at the Virginia Commonwealth University, in Richmond, noted that nearly 70 percent of the more than 100,000 concussions experienced each year across high school, college, and professional football come from helmet-to-helmet hits.
A prior study in Neurosurgery of the size and position of players most often experiencing concussions found that the players most often concussed were usually not the big guys on the field—they were quarterbacks, wide receivers, and tight ends, with defensive players further behind. “It’s not the weight of the individual that correlates with concussions, but rather the speed at which they are moving on the playing field,” Colello said. “These players are getting up to full speed on the open field and then they are getting hit, and that hit occurs within 10 milliseconds.The g-forces are absolutely astounding that take place.”
An average player can receive as many as 600 helmet-to-helmet hits in a season, he found, with gravitational force ranging from 20 to 150g. G-force is a measure of acceleration (weight per unit mass, for you science folks) and anything over 84g can be enough to slosh the brain forcefully inside a player’s skull after an abrupt stop. The faster the runner, the faster the impact and the more force behind the hit.
“We know we’re not going to be able to change velocity—because the players are only getting faster and bigger—but we can change the time in which the impact takes place.”
Colello showed off early prototype studies for a new type of football helmet embedded with neodymium magnets, the strongest type of permanent rare-earth-element magnet. An N52 magnet, the type used in the prototype helmet, can repel something 300 times its own weight, so the 1 to 2 lbs. of inserts on the top and sides of the helmet can push back against another helmet moving with more than 300 lbs of force.
The researcher used a standard drop test, in which the helmet is dropped from 6, 12, 24, 36, and 48 inches, using gravity to simulate different levels of force: For example, dropping a helmet 48 inches simulates 120g of force on impact, a common hit force on the playing field. Colello found, dropping the helmet with a 10 lb. weight, the repulsion of the magnets slowed that impact significantly, “putting a break on the system” and reducing a 120g impact to an 88g impact. It reduces the levels of force at the other heights to less than 55g—below concussion level.
The magnet system is still in very early stages of testing, and it’s way too early to tell whether this sort of technology can be used to prevent or reduce the severity of concussions in high school[SDS: OK/-DV] junior varsity and varsity sports, but at minimum, it would be a great experiment for a high school physics teacher to get the athletes in the room interested in science.
A version of this news article first appeared in the Schooled in Sports blog.