How can you tell if a horse has been in a rodeo?

I bought a 10 yr mare at an auction, she is a mean and spitful horse. I think she might have been used as a rodeo bronce witch wasn't mentioned of corse when they brought her out to show. I can't even brush her hindend or the tummy by the flanky without risking getting mule kicked, I was thinking she was abused as well. I can't even touch the top of her head without her trowing a fit. If there is anybody out there that can help me please do so.