Quote Originally Posted by Buffalobiian View Post
Continuing the RasenShuriken talk, the Nature chakra allows him to throw it, so he does, avoiding any damage to his arm. If sustaining the jutsu caused damage, he would have found out during training already.
(...)
Now that he can throw it, the problem's solved, only now it actually has a minimum range.
that's what I thought, too. It seems to be the most plausile explanation