Don't get that perk. You have to hit them with a backwards power attack for it to work (which is almost impossible), and it only works 25% of the time. It's a waste of a point IMO. You can't really count on it in a pinch.
The enchant is much better (although I never personally ran into it).
Trust me, the perk is better spent elsewhere. It's a pretty weak 100 pointer.
"So far the perk seems like it doesn't work. A weapon with a paralyze Enchant is highly effective though."
It's not that it doesn't work, it's just you have to hit them with a backwards attack. The only way to do that is if you hit the power attack button backwards while they're swinging in at you forwards, and even then you have to hit it at the exact moment to get it to work. I have gotten maybe two procs off of it. It's worthless.
Yea even if you don't find it (I'm 81 and I've never found it) it's still not worth it. It's just too hard to hit with and too low of a proc rate. Try it right now if you don't believe me: go try to kill something only using backwards power attacks.