T.C.
Hi Cyndi,
as an OT, I'd say they're a "gimmic."
I don't know if you remember the Dr. Scholls sandals from the 1980's that were supposed to do the same thing. They had a contoured base that was supposed to force you to use more muscles when you walked (and give you nicer legs). They worked for no-one, but Scholl's made millions.
If you like the way they *look* then buy them, but don't expect to get nicer-looking legs out of it.
t
YUP! after reading what everyone else says: almost definitely some kind of gimmic... LOL!