It's not OK to keep banging your head around. As an example, Second Impact Syndrome can result in death although that is rare. If you get a second impact before the previous one has healed, even if the impacts are minor, then the brain overreacts and pumps out too much damaging inflammation.

If those kids are banging their heads then they should be wearing helmets designed for special needs patients for their safety and for yours. You can also wear a padded hat insert like the Unequal Dome 2 for your own safety.