I don't really know anything about physics so excuse me if this question is stupid.

I've read on several threads that objects/ humans need to have a certain mass to cause a concussion. Like a small child for example cannot cause a concussion because it doesn't have enough body mass.

Does that mean that any object which doesnt have enough mass ( I don't know say under 5 pounds) cannot cause a concussion no matter how hard I hit my head with it?

I'm just really confused by all this stuff about g force and would really appreciate it if someone could explain it to me. I believe that once I have understood the basics of what is a concussive impact and what is not I can finally get over my anxiety.

Thank you