Join Date: Apr 2009
Location: Queensland, Australia
Chances are that this horse could be a little awkward with where she places her during the transition. Some horses concentrate so completely on what their rider is doing that they find it difficult when it comes to changing pace. I have a horse like that. He concentrates so much on what I'm doing that he forgets where he's putting his feet. There's nothing wrong with his paces or transitions on the ground. Just with a rider and going from trot to canter, as it is a difficult transition.
As you said your horse is very sure footed, check the hindquarter muscles, she could have difficulty pushing herself forward, hence the head thing. I think someone's already mentioned this.
That's just some suggestions. In the end, there could be nothing wrong with her, it's just how she does things. I have a horse who holds his neck waaay up in air. Not for any particular reason, that's just the way he learnt to do things when he was younger. If it just seems odd (isn't pain) and doesn't worry you, then you're probably best leaving her as is. She's probably perfectly happy doing it, even if it seems unusual. =)