At the walk he's fine, but once you start trotting he just wants to canter. I have to constantly seesaw to keep him at a steady pace, the second I stop he canters. At the canter he just wants to go faster, again unless I seesaw, although it's not so bad as at the trot. Sometimes the problem isn't even there, but only about 10% of the time. He's ridden in a hackamore since he absolutely cannot stand a bit. I don't work in an arena ever, I'm only ever out on the trails, so boring circle work is totally out of the question. Also, his back is fine, no soreness or anything. What can I dooooo?!