I went back to my trainer for my mare that I bought from him, and he told me about what happened when they first got her--- she was a lesson horse, so they didn't get very picky or particular, as they only wanted to meet the demand of what kind of rider would be on her (intermediates). She simply doesn't flex easy, and can't give to pressure the true Dressage way. Bending laterally is very much possible, she can be amazingly flexible through her body that way, as was pointed out to me; getting her on a good bend really gets her to use her back and step under, but the popular picture of being "on the bit" with a head on the vertical with that activity... not for her. She's thick through the throat and jaw, the head isn't set well, paired with her croup being a tad higher than the wither. Putting her over cavelletti, she shows off beautiful suspension and impulsion.... while Rudolph leads the way with her nose. Trainer says strengthening her back is where to focus-- response is what we're looking for, not a topline and not a "frame." Collection for her means keeping a shortened/slower pace and still being energetic and responsive: organized, really, "on the aids" but not truly "on the bit". So, girl can't have a "correct" contact or naturally put weight on her bum when asked off the bat.
Makes me think of some other horses out there. Down the street, there's a pony with a croup so high, you can slide a kid down it into the withers. When I first saw him, I thought he must ride terribly. He did. He would go around with a dropped back with his nose out further than my mare does, and it was all he could do to keep a steady pace without rushing or wobbling around. This year, it's like his bum dropped an inch! He doesn't have a neck issue so at this point his girl can ride him on the vertical with his impulsion, and it looks very good with his croup at the level you might see on the average pony, not like a dinosaur pony. Compared to other horses, he's plain or still sub-par in some areas, but compared to what he used to look like, he's AMAZING. For those of you wondering, I think he's a Welsh, dazzling white coat with a puggy nose
So, goes to show it's about the personal best of each horse and what they can do. It's neat to need to devise specialized training for these fellows, as they certainly tend to break the mold. Pain in the rear end sometimes (literally) but fascinating nonetheless
Now, has anyone heard of trainers/physical therapists that specialize for this? Training horses with body issues? Lawdy, that would neat if there are some around.