What are those leg spring things called?

There is a commercial on TV now where the people have these things attached to their legs that enable them to jump really high. They are like pogo sticks, but they are attached to each leg. I remember hearing how they mimic the leg structure of a grasshopper or something like that. Any clues as to what they are called? Where can I get some?

They are called Powerisers - like power riser’s I guess.

I saw them recent ly at a Ren fair of all places… and asked what they were… I’d love a pair!

Thank you very much.

Here is how you can make your own. :wink:
http://www.cockeyed.com/incredible/shoes/shoes.html