Horse bucking or hurting?

My Percheron/TB mare has been doing little hops when I canter her lately. I had a vet come out and assess her and ended up doing chiropractic work on her. She seemed fine for a few weeks afterwards. When she does her "hops" its not like she is bucking to get me off by any means. Its more like she is kicking up to get an imaginary fly on her belly than bucking. It happens mostly when I apply pressure with my outside leg to either speed her up or keep her on a circle. I have been frustrated with this for a while because I can't tell if it's just a habit that I need to work through or if something is actually bothering her. I can't really afford to pay another $250 to have a vet do chiropractic work again if it's not going to work. Any advice? Thanks in advance!

I think she is maybe trying to just avoid your leg. She could be a little sensitive and may just try to......how can I call it??? I'm not sure. Almost like a horse does with his head when he comes behind the vertical, trying to avoid the contact with your hands. Maybe she's doing that with your legs.

Or maybe in her past she was trained to react to a leg aid and she still associates it with your aids of trying to make her faster or something. Lots of schooling may help get rid of this habit.

Other than that, I'm not sure what else it could be. Hope that helps. = )