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
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
Subhash said cushions and water- or air-filled pouches typically
have been used to help protect against linear blows.
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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
"Many people believe that the rotational forces are more
important than linear when you talk about concussions," Mueller
(Editing by Kevin Gray and Gunna Dickson)
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