My horse is almost three. I have started riding her, she was doing really good, until she flipped over and stated rolling, I got off of her before she rolled on top of me... But I do not know why she did this, and how do I stop her from doing it again? She also twists her head down really low making me fall off balance. I do not know why she is doing this, I have tried to put my foot forward so she would smack it was to would twist her head, but it did not faze her at all. I am thinking maybe if a started her under bit that she would listen more to me when I am on her back. She was doing really good on the halter, but she just started doing this, I have also tried to take the whip along, but it makes her to nervous. Can anyone give me ideas??