it's more effective to throw or knock the Infected away when they try to grab him instead of carrying a weapon
No. No it isn't. Just no. All the nope. Even if he's a scout crawling down a cave that's barely wide enough for his body, that's a big hell no.
The martial arts we're familiar with today are simply variations on the duel. The combatants compete under a strict set of rules, and the intention is that both are alive at the end of it. "What about MMA/vale tudo/whatever backyard brawler?" I hear someone ask. They still have rules, most notably that neither person is wearing body armour or carrying a weapon.
This is very different to the kind of fighting where you're actually aiming to kill someone, or at least to prevent yourself being killed by another someone who's actively trying to kill you. One of the more effective martial arts is jiu jitsu; and every jiu jitsu practitioner will tell you that it was intended as a backup skill for when the samurai had lost his sword on the battlefield or was attacked by surprise.
So, back to the zombies. They don't play by any kind of rules - they want to kill you and eat you. So the scout has a weapon for self-protection. He just does, because if he doesn't have a weapon then going anywhere near a zombie is straight-up suicide. He does have the choice of what weapon to use though, and being a pacifist he doesn't take the obvious options of swords or axes to cut heads off.
The obvious choice is a boar spear. This may sound pretty damaging, but these are zombies, right? You can kill them by cutting off their heads, but damage to their body doesn't signify. So a boar spear is perfect - the zombie walks into the spear and impales themselves on it, and the lugs stop the zombie working its way down the spear to get to you. Flip a rope round the zombie (a weight on the end of a line will loop the line round the zombie nicely if you throw it right), attach the ends to cleats mounted on the side of the spear, and you've got the zombie securely attached to the spear. Now you have leverage on your side, so you can control the zombie whilst your friends tie its arms and legs.
Oh, rope skills for achieving that. You did want an unarmed martial art. I give you Hojōjutsu, the Japanese martial art of tying up people (especially resisting people) quickly and effectively. Like most unarmed martial arts, subduing the opponent relies on pain submission which clearly won't work on zombies; but we've dealt with that with the boar spear, and the basic concepts of restraining limbs will still work perfectly well.
Unarmed combat against a zombie though, did I say no enough times? No. Not enough times. It's a no.