I have no idea what he was doing, but I have never felt anything like it. It felt as though he had a post for one of his legs, he was twisting and lurching... Not close to bucking or anything, just all jangled and bumpy. We stopped right away and he continued on quite sound... Could he have been cross cantering?
I cantered him when we first bought him, and he was like a coiled spring, powerful and smooth. I currently have no place to lunge him to check it out... Any ideas?