It'* worth being looked at bud.

I folded my right thumb back like that several years ago. It still bugs me occasionally, like now....

I'll echo what others have suggested - have a doc look at it. Whatever'* damaged in there could lead to complications when you get older. Things like arthritis, limited movement, chronic pain. You'll be old someday (trust me on this) and those injuries when you were young and capable will come back to haunt you if you don't do something about it.

Guys, remember we are talking about a young child here. He may have broken a growth plate, which could cause severe mutilation as he matures.