A new design of American football helmet could better protect players against glancing blows experts say contribute to most concussions.
Most protective sports helmets are 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 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.
Subhash says his new strategy makes use of fluid-filled pouches that his tests show also protects the brain from the rotational or shearing force of off-centre 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 armour for the military.
Subhash said cushions and water or air-filled pouches have generally been used to help protect against linear blows, but to blunt shearing or rotational forces he adds pouches filled with non-Newtonian fluids that increase resistance when stressed.
He said that 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.
The new helmet is due to be unveiled later today and Subhash says he will demonstrate its effectiveness on Jan. 20 for venture capitalists, who could fund wider scale testing and manufacturing.
Subhash, along with his collaborators UF neurosurgeon Ian Heger and UF radiologist Keith Peters, hope to have low-cost pouches suitable for retrofitting existing helmets available in stores within two years and he says the pouches also can be used in helmets for the military, firefighters and constructions workers.
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.”
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.