The other day I got on her quick and was focusing on keeping her on the wall, anytime I put alot of leg pressure on her she'd pin her ears, swish her tail and sometimes even kick out. She is an aggressive horse on the ground but for her to act up at ALL with anyone on her is completely out of character for her. I've been thinking we need the chiro out but this seems like another issue. Any idea why she's doing this?
ETA - she is fine when you're riding her, it's just when you add extra leg pressure she gets pissy.