Knight's helmets were actually heavily padded, with most knights wearing heavy padded linen garments over their torso, arms, and head. Nicer helmets would have

Knight's helmets were actually heavily padded, with most knights wearing heavy padded linen garments over their torso, arms, and head. Nicer helmets would have a leather strap system as well. Many helmets appeared to have integral liners, although the linen has rotted away and only left the rivets where they were attached. With the advent of plate armor, offensive techniques began to focus on concussive force in order to disable combatants, including war hammers and maces. A blow to the head with only a bit of steel between your skull and a mace would be a fatal experience without any padding. Even with padding it was notorious for deafening and disorienting knights, due to noise and (presumably) brain injury.