Haha! I know what you're talking about, Vegas and Nevada both do it. As does my dachshund Reno. I never thought that it meant anything more than a good stretch. I'll be sure to keep up with this thread to see what everyone else thinks.
My friends call it her ballet streching! LOL Her back paws fold under as she walks stretching out her back legs. I thought she was just weird! INteresting that others do it as well, I've never had a dog do it before her!
my puppy does that too. every time she gets out of her cage she stretches like that. She also will get in that position to scratch her belly on the the ground. she pulls her body with her front legs and has her back legs sprawled out. I saw she is training for the marines doing low crawls. She will do it under all our kitchen chairs and in the grass.