Now I know Border Collies are different from many other breeds, and need occupying, but I'm really not sure this is the way to go about it. Here you can read an article about Kirin who has been taught to do squat type exercises on command. All very well and good, except I'm not sure how good it is for her back legs. I always worry about dogs who are required to even walk upright on their back legs a lot, but standing on them and raising and lowering herself must be putting a ton of unnecessary strain on Kirin's legs.
She wags her tail as she's doing it, and do like the clever way she tries to find a handy wall or piece of agility equipment to lean on for balance.
Is it clever training? - yes it is. Is it good for the dog? - I wouldn't have thought so, but if any vets or other health experts reading can shed light on the subject, please do.