Scientists at Lawrence Livermore National Labs, one of the government's top research facilities, have said that by adding just a quarter-inch, or even an eighth of an inch, of padding, helmets had a 24 percent reduction in force to the skull.
"When you look at the accelerations that can cause injury, just a small increase in thickness can knock that acceleration down to a point where it'll make very severe injuries potentially a little less severe, and very light injuries maybe not happening at all," explained Michael King, the study co-author and a Lawrence Livermore mechanical engineer.
The yearlong study, funded by the Pentagon's Joint IED Defeat Organization, used computational simulations of impacts on the head and helmet.
To get accurate data, it turned to professional football, where concussions are also a big concern, and tested the thicker foam systems used by NFL players against the spongier pads used in combat helmets to see which worked best.
It concluded that the Army's helmet padding worked just as well as the padding in NFL, but that there just needed to be a little more of it.
Currently, Kevlar helmets come with 3/4-inch foam pads inside. But while adding more padding may sound like a simple fix, it would require soldiers to wear a helmet one size bigger, and carry additional weight on their shoulders all day. Helmets normally weigh about 5 1/2 pounds, and a larger size would add about four ounces.
Soldiers say their gear is heavy enough as it is, and for now, the Army is balking at the trade-off.