I think it was far less than an adrenaline rush or anything of the sort. If you read the story, and act it out in your head, the boy was wandering around gathering things for Kiyashko already...and Kiyashko's attention was occupied. The boy didn't barrel into him from the front, where Kiyashko would have a chance to defend himself or put the boy down before harm could be done, he just rushed him from behind and stabbed him in the back. While the wound wasn't enough to kill him, it definately was enough to get his attention...he turned his attention on the boy who had hurt him, and the sister took the opportunity to run. He didn't fend him off as much as simply distract him...but it was enough and the kid had more guts than most men who claim they are brave.

well when the human body is pushed to limits of intense fear or death of itself or family, it has been known to tap into a different level of strengths. See we on average all only use about 1/3 of our strengths, The reason we cannot use our totally strength of our muscles is purely because if we did it would rip the mucles and tendons from the bone. Now its been known that when a person is pushed to the point of death then sub consiously they tap into their strength and there mind basically says to itself, well its better to lose use of our arms for a little while then die. Make sense? There was a average build male hiker who had a boulder fall on him and he lifted it off of himself, well the boulder weighed about 1200 pounds, the highest lift for free weights from people who train in this their whole life is about 900 pounds. So personally i think this is what happend to the boy he seen his family in danger and his body was pushed to points that he did not know he had? basically?

After reading the story and all other websites that carried the story, I can see how it was possible for the seven year old Zhenya Tabakov to stab and Thus free his sister from 35 year old Sergey Kiyashko.

I think it was possible due to the fact that the pedophile was probably very distracted with the heinous act that he had wanted to commit on Zhenya's Sister Yana Tabakova, that he did not notice the fact that the seven year old had a weapon and was intent on attacking him.

That seems to be the only logical explanation, I feel sorry though that the young lad had to lose his life,I think his act of valor fully deserved that award.