Originally Posted by Kayty
If she's on the forehand, her head with bob as she tries to keep balance. If you watch a school horse cantering around with a beginner on board, its head will be bobbing quite distinctly due to it's weight being on its forehand.
Otherwise, certainly rule out soreness (teeth particularly) and lameness. Does she trot out even on a hard surface?
What do you mean trot out on a hard surface? And no she's not lame. But that would make sense her bobbing to keep her balance when I go slower but she also does while regular speed but not as derasticlly. But when I let her go and gallop she doesn't do it. I'm Gina have the vet come out and check her teeth just to make sure she doesn't need a float.