Watching a highlight reel of big hits never fails to elicit cheers and audible gasps from fans. But the cracks, thuds and smacks that make up the soundtrack to American football also accompany a growing problem for the full-contact sport: concussions.
Those big plays with skull-rattling hits are leaving players with irreversible brain damage despite expensive safety gear meant to protect them from harm. Mississippi State University’s Mark Horstemeyer says this problem stems from lack of understanding about what causes traumatic brain injury.
“The standard for developing football helmets doesn’t take into account many real-world conditions,” explained Horstemeyer, a professor of mechanical engineering. “As a result, many helmets are designed to look good but not be as safe as they could.”
Horstemeyer and a team of researchers from across the James Worth Bagley College of Engineering have developed tools to better understand how these helmeted collisions affect the brain and surrounding tissue. They’re now using that knowledge to develop more effective protective equipment.
“Our design might not be better looking, but it will be safer,” Horstemeyer said.
The group started with a virtual model that shows—from the smallest atom at the microscale to the tissue that can be seen with the naked eye—how the human head responds to the force of a collision.
“Our model has been able to capture a level of detail that shows that vibrations actually travel around the skull then through the brain, which changes our understanding of where, when and how injuries occur,” explained Raj Prabhu, a biological engineer on the team.
Created as part of Prabhu’s dissertation, the virtual model of the head allowed the group, which includes fellow biological engineering faculty Lakiesha Williams and Jun Liao, to see that most brain injuries don’t come from the initial hit, but rather the stress waves it causes. These waves move back and forth through the tissue until they dissipate, leaving damage in their wake. And while conventional helmets help absorb some of the initial impact, they don’t do anything to stop the resulting shock waves.
To counter this oversight, Horstemeyer’s group studied some of Mother Nature’s hardest heads—woodpeckers and rams. The team found that the unique composition of the red-bellied woodpecker’s beak, combined with the spiral structure of its hyoid bone, prevents the bird from sustaining brain injury, despite absorbing shocks up to 10 times greater than those players withstand on the gridiron.
Similarly, the spiral nature of rams’ horns seems to provide an escape route for shock waves.
“If you look at a ram strike, the shock wave seems to go all the way through its body,” Horstemeyer said. “But what actually happens is the shock wave comes around the horn to the tip, which transversely vibrates very quickly and mitigates the shock.”
Horstemeyer said incorporating spiral structures into a helmet could make a significant impact on the number of concussions incurred on the field. The issue, he said, is how to achieve this while still having a helmet that works in game-time conditions.
“We know that if you actually had a soft foam on the outside of the helmet it would be more protective, but obviously that design won’t work because the foam would easily tear and absorb water,” Horstemeyer said. “Our job is to think outside the box yet still have something that’s acceptable in the game.”
The group’s proposed design addresses the three main components of a helmet: the outer shell, the facemask and the liner. It uses advanced materials, like Kevlar and magnesium alloys, to construct the helmets’ outer, protective shells and facemasks. These materials offer more strength and durability than commonly used polycarbonate materials. They will also help reduce the overall weight, which can help prevent some injuries in addition to making the helmets more comfortable for extended wear.
“Helmets are tested for safety without their facemasks attached and they all pass. But when you add the facemask, the additional weight causes the helmets to induce greater torque thus inducing greater injuries,” Horstemeyer said. “It shifts the center of gravity, which creates more rotation in the neck and increases vulnerability for head and neck injuries.”
Horstemeyer explained that the grooves, ridges and intricate facemasks featured in modern helmet design might look nice, but they negatively affect safety by adding weight and increasing the likelihood that the helmets will catch on each other in a collision.
“Our facemask and shell joint design won’t be as heavy and it will be smooth as a baby’s rear end, but you won’t actually see a lot of difference,” Horstemeyer said.
The biggest design changes will affect the inner lining of the helmet. Horstemeyer said the group’s design replaces the regular liner material, which mainly serves to ensure a secure, cushioned fit against the head, with specially-developed foam that incorporates rams horn microstructures into the material.
“The lining of our helmet will have these little ram horns so that if a shock wave comes in it will go through the horns and dampen out,” Horstemeyer explained. “That means many of the damage-causing vibrations from a strike to the outer shell will never reach the player’s head and brain tissue.”
The group has patented and will produce these helmets through the start-up company Rush Predictive Design Technologies, a joint venture between Horstemeyer’s Predictive Design Technologies and Rush Sports Medical, founded by Dr. Sonny Rush of Meridian.
Horstemeyer said the team plans to introduce its helmets first in college football, but that his target is the million children and teenagers who take the fields in their hometowns each year eager to prove their athletic prowess.
“I almost get a headache just looking at some of the hits these players take, but I really believe that this helmet we are designing will help take care of our children and athletes and protect them from permanent injury,” Horstemeyer said.