Researchers in Florida believe they have come up with a low-cost way to improve football helmets and better protect players against the glancing blows that experts say contribute to most concussions.
Protective sports helmets on the market today are largely designed to absorb shock from direct linear hits, like head butts, which force the head straight back, says University of Florida (UF) engineering
professor Ghatu Subhash.
But Subhash's new strategy makes use of fluid-filled pouches that, his tests show, also protect the brain from the rotational or shearing force of off-center hits on helmets.
"The fluid-filled cells within the helmet respond, so no matter the angle of impact, the helmet automatically protects any part of the head," said Subhash, who came up with the idea while working on improving helmets and body armor for the military.
Subhash, along with his collaborators - UF neurosurgeon Ian Heger and UF radiologist Keith Peters - is set to unveil the safer helmet on Thursday. He will demonstrate its effectiveness on January 20 for venture capitalists, who could fund wider scale testing and manufacturing.
Subhash said he hopes to have low-cost pouches suitable for retrofitting existing helmets available in stores within two years.
The pouches also can be used in helmets for the military, firefighters and constructions workers, he said.
A growing body of academic research shows the repeated hits to the head to which football players are subjected can lead to chronic traumatic encephalopathy, a condition linked to the loss of decision-making control, aggression and dementia.
The National Football League agreed last year to pay more than $760 million to settle a lawsuit brought by more than 4,500 former players.
Subhash said cushions and water- or air-filled pouches typically have been used to help protect against linear blows.
But to blunt shearing or rotational forces, he adds pouches filled with non-Newtonian fluids, which he says increase resistance when stressed.
Think kids' Flubber or Silly Putty, which can flow or break depending on stress, or chilled caramel ice cream topping which is easily spoonable yet stays put in an overturned jar. Non-Newtonian fluids also are used in some modern automobile shock absorbers, Subhash said.
Subhash said when one of his fluid-filled cells is struck, the fluid squeezes through a tube into a second cell, thus neutralizing the force. The fluid then returns to its original cell, making the pouches reusable.
Concern over the long-term impact of blows to the head has created a market for expensive helmets that claim to protect players from concussions.
"There are no helmets that will protect against concussions," said Frederick Mueller, research director for the standard-setting body, National Operating Committee on Standards for Athletic Equipment.
"Helmet manufactures may say that, but none at the present time protect against concussion injuries," he said.
Mueller's organization has warned about the limitations of the testing used in a popular 5-Star helmet rating system created by Virginia Tech, including the lack of consideration of rotational forces.
"Many people believe that the rotational forces are more important than linear when you talk about concussions," Mueller said.