The Search for a Safer Helmet
Novel helmets designed to protect players from concussions are coming to market, but experts still need more data to fully understand the injury.
Long after the winners of Super Bowl XLV have taken home the Lombardi trophy, this season will be remembered for new efforts to mitigate the seemingly inevitable head injuries sustained by so many football players.
The average player sustains an estimated 950 impacts to the head during a season. These hits could result not only in concussions but also long-term brain damage. In response to the greater awareness of head injuries, the NFL made significant rule changes this season—harsher penalties and heavy fines for helmet-to-helmet hits or hits against defenseless players. But another way to protect players comes from better helmet technology.
Riddell, the official equipment manufacturer of the NFL, has released a new type of helmet designed to help reduce concussions. The Riddell 360 reduces the force of impact to the front of a player’s head, where 70 percent of hits occur, says Thad Ide, Riddell’s senior vice president of research and development. Ide adds that 70 percent of concussions result from hits to the front of the helmet.
Riddell has gathered statistics on head injuries using its own HIT technology, a system that employs sensor-equipped helmets to measure the location, magnitude, and direction of hits experienced during a game or practice. To date, the system has gathered data on over 1.5 million head impacts. The NFL recently announced that it will use the HIT technology to measure head impacts during the 2011 season. The league is working to advance the system and build new sensors that can be placed not just around the top of the helmet, but also behind a player’s ear and in a mouthpiece for more accurate readings.
Riddell redesigned key aspects of the helmet to better protect its front section. Faceguards are normally made of carbon steel and attached to the upper front of the helmet; so when a player gets hit in the face, energy is transferred to the front of the head. In contrast, the facemask on the Riddell 360 is made of a hybrid of carbon steel and a lightweight, flexible material. It’s attached to the side of the helmet with hinge clips, which means the faceguard flexes on impact, absorbing more of the energy before returning to its original shape.
Riddell researchers also created a “face frame structure,” a continuous padding arrangement made from materials that help reduce the amount of force transmitted to the player’s head from a hit to the front of the helmet. The padding inside the helmet has a hexagonal design that forms well to the player’s head, says Ide. And the helmet has an inflatable liner in the side and back for a custom fit. This prevents a player’s head from moving around inside the helmet, and keeps the helmet from popping off.
On January 10, the Riddell 360 was worn for the first time during a real game, when University of Oregon football star LaMichael James wore the helmet during the college national championship game against Auburn University. Ide says the helmet, priced at over $400, will ship to all Division 1 college teams this spring.
Another major challenge in helmet design is protecting against rotational or angular accelerations, hits that cause a player’s head to rotate or spin slightly, which most often lead to concussions. Since 2007, the National Institutes of Health (NIH) has been funding studies, using the HIT system, to measure how this type of head impact causes injury. The HIT technology measures both rotational and linear acceleration of a player’s head. Linear acceleration is the result of a direct hit that causes a player’s head to move back and forth. The resulting reaction force is expressed in g-force (with one g being equal to the force of gravity). Research conducted by the NFL has determined that 98 g is the threshold for concussions.
“[Riddell’s] helmet concept and design is certainly unique,” says Joseph Maroon, a professor of neurosurgery at the University of Pennsylvania Medical Center and the team neurosurgeon for the Pittsburgh Steelers. “But the problem is that there is a lot about concussions and head injury that we don’t fully understand.”
This is a key issue for those researching ways to protect football players. A study published in the Journal of Athletic Training in December 2010 found that brain trauma can be caused not only by hits that leave a player woozy, but also by the accumulation of smaller hits.
“The discussion that is happening now is, which hits do you want to protect against? The huge catastrophic concussions, or the smaller hits that a player takes 50 times a day?” says Chris Nowinski, president of the Sports Legacy Institute, a nonprofit organization based in Waltham, Massachusetts, that studies brain injury in athletes. “Frankly, I don’t think people know which way to go at this point,” says Nowinski.
Rick Greenwald, president of Simbex, a research and product development company in Lebanon, New Hampshire, and principal investigator of the NIH studies using the HIT system, says researchers still don’t know how much rotational motion causes a concussion, and therefore don’t know how much they need to reduce it in order to prevent concussions. (Simbex specializes in biomechanical feedback systems and originally developed the HIT technology, which was acquired by Riddell in 2004.)
The need for better protective gear has also inspired some more experimental designs. Michael Princip, an industrial design engineer, recently received attention for his Bulwark helmet, which incorporates layers of padding at variable thickness and density beneath a hard outer shell made of polycarbonate. The inner layers are calibrated to reduce the amount of energy that reaches the inner shell that surrounds the player’s head. The helmet is also segmented so that sections of the helmet can be padded differently depending on a player’s position—quarterbacks, for instance, endure most forces to the back of the head. Princip is currently building a second prototype for testing.
Another design that has been in development for eight years is the Gladiator, built by Brett Straus, an industrial designer at Protective Sports Equipment, a private company in Pennsylvania. The helmet has a soft outer shell made of polyurethane foam over a hard outer shell helmet. It also includes several inside layers designed to manage the energy of hits.
Any effort toward technology innovation should be applauded, says Greenwald. However, he says, all of these designs need to be studied carefully in the lab and on the field, and be evaluated by the National Operating Committee on Standards for Athletic Equipment.
There is growing concern over the way all helmets are tested and rated for safety. Sen. Tom Udall (D-New Mexico) is asking the U.S. Federal Trade Commission to investigate “misleading safety claims and deceptive practices” in the selling of new football helmets and reconditioned used ones.
Nowinski says brain trauma and concussions are always going to be a problem in helmeted sports. “There is a lot about head injuries that we don’t know and don’t understand,” he says, “and that is going to be true for a very long time.”
Brittany Sauser is a reporter and senior Web producer for Technology Review.
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