The professional football season kicked off Thursday, and with it came debate about head injuries.

One company that's trying to make a difference is Seattle start-up Vicis, which makes helmets that it says reduce the severity of head impacts. The Vicis Zero1 helmet's outer shell acts like a car bumper because it flexes on impact and immediately bounces back.

Vicis says players from 28 of the 32 NFL teams wear its helmet, including Russell Wilson, LaMar Miller, Golden Tate and Doug Baldwin.

A recent study of the brains of deceased NFL players found signs of degenerative brain disease in 99 percent of former players. Though concussions are not totally preventable, the Zero1 beat out all other helmets in both the Virginia Tech Helmet ratings and the NFL/NFPL helmet laboratory performance tests this year.

In May, Vicis was awarded a contract from the Army to improve its combat helmets.

Each helmet costs $950. The company says it's also working on an youth version.