Results revealed that without the face shield, the ACH slightly delayed the blast wave's arrival but did not significantly lessen its effect on brain tissue. Adding a face shield, however, considerably reduced forces on the brain.
The study, published online Nov. 22 in the journal Proceedings of the National Academy of Sciences, contradicts previous research that suggested that the ACH could mitigate brain injury in service members -- the most common injury sustained by soldiers in Iraq and Afghanistan.
"This study really has two key contributions," Radovitzky said. "First, that the ACH doesn't help a lot for blast protection, and second, but it doesn't make it worse. We are not saying anything negative about the ACH, just the opposite. With the helmet, we saw a lot of improvement compared to an unprotected face."
Dr. Michael Lipton, associate director of the Gruss Magnetic Resonance Research Center at Albert Einstein College of Medicine in New York City, said one of his concerns about the study is that the only thing modeled was the effect of a blast.
"Really, there's no such thing as an isolated blast," Lipton said, explaining that the impact typically knocks one to the ground or causes the head to hit other objects. "There are blast waves, but an impact component also. Very commonly, there's a whole spectrum of injury. It all depends on the position and proximity of the patient to the blast."
Lipton pointed out that a face shield wouldn't just help soldiers involved in heavy explosions, but also in smaller blasts that happen on an everyday basis.
"It's not uncommon for these soldiers to get exposed to multiple blast injuries without being removed from repeated [combat] exposure recognized as significant injuries," Lipton said. "Protection might even be more efficacious in repeated impacts."
Radovitzky said many details need to be addr
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