A new study found that risk of concussion among football players may not be significantly lowered with helmet add-ons. Outer soft-shell layers, spray treatments, helmet pads and fiber sheets are the most commonly used helmet add-ons.
"Our study suggests that despite many products targeted at reducing concussions in players, there is no magic concussion prevention product on the market at this time," said study author John Lloyd, PhD, of BRAINS, Inc. in San Antonio, Fla., and a member of the American Academy of Neurology.
Researchers modified the standard drop test system, approved by the National Operating Committee on Standards for Athletic Equipment, by using a crash test dummy head and neck to more realistically simulate head impact. Sensors were placed in the dummy's head to measure linear and angular rotational responses to helmet impacts at 10, 12 and 14 miles per hour.
Using this device, BRAINS researchers evaluated four football helmet add-ons: Guardian Cap, UnEqual Technologies Concussion Reduction Technology, Shockstrips and Helmet Glide. Riddell Revolution Speed and Xenith X1 football helmets were outfitted with each of these add-ons and impacted five times from drop heights of 1.0, 1.5 and 2.0 meters. Linear acceleration, angular velocity and angular accelerations of the head were measured in response to impacts.
The study found that compared to helmets without the add-ons, those fitted with the Guardian Cap, Concussion Reduction Technology and Shockstrips reduced linear accelerations by about 11 percent, but only reduced angular accelerations by 2 percent, while Helmet Glide was shown to have no effect.
"These findings are important because angular accelerations are believed to be the major biomechanical forces involved in concussion," said Lloyd. "Few add-on products have undergone even basic biomechanical evaluation. Hopefully, our research will lead to more rigorous testing of helmets and add-ons."
The American Academy of Neurology, an association of more than 28,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, brain injury, Parkinson's disease and epilepsy.