Board Thread:Theories and Speculation/@comment-26998824-20160103023450/@comment-25632268-20160127113545

UltimaDude wrote: Well that wasn't my point. I was saying that after Naruto completed the Rasenshuriken, he still thrusted it when battling Kurama

No, he didn't. He used Rasenshuriken once during this battle and he threw it. What he thrusted was something he called Sage Art: Gargantuan Rasengan. Chapter 497.

I believe that chakra, when controlled properly, can't hurt the one who is using it. Naruto sucked at chakra control for most of the manga so he got bruises when mastering basic Rasengan and got hurt at first by Rasenshuriken.