Fairy Tale Labratory

Clip from Rusalochka (The Little Mermaid), 1976

I found this article today on Yahoo's front page about scientific reasonings behind fairy tale phenomena. It's a very short, but interesting read, the sort of piece that, much like a fairy tale, leaves the reader craving more. So, I started Googling and found the following article as well.

"Fairy Tale Physics: Myths and Legends Explained" from National Geographic News.

But, I still wonder, if scientists can explain the Little Mermaid's absent voice, why not explain the stabbing sensation she felt with every step? Did the old hag pinch the mermaid's nerves too? I ask only because that was my favorite part of the story and it seems like people have forgotten about it since Disney decided to omit the walking-on-knives portion of the tale.