Yep. As everyone above has stated. I have a halter bred QH that is a real bear to get on her hind end. It's a shame too, because WHAT a hind end! LOL.
Trails, hills - making them walk it, rather than trot or canter up, if you have any where that is sandy - that's great, as well as good deep fresh plowed fields, cirlcles, figure 8's, Lots of backing up at stops, groundwork for turning on the haunches, then in the saddle, ground poles, actually, jumping work is good too. Millions and millions of circles. Fun fun fun.
Ask Often, Demand Nothing, and Reward Generously.