Ever since Diego turned 8 months he has developed the charming behavior of plopping his butt down on the pavement during our walks and refusing to move. I take him for a 1.5 mile walk in the morning and it isn't much fun lately! I bring lots of treats with me, and have successfully taught him "heel" in all this. But he still does it!
I think the actually problem might be that he's bored with the walk we take. It's the same one every day. He just has sooooo much energy I have to walk him! It's a leisurly walk, it's not like I'm jogging him or anything. He gets his puppy zoomies when we get back to my apartement too (love it!).
Oh, and if I take him somewhere completely different he doesn't do it!