 When pain is ruled out as a factor, rider error is a very common cause for refusals; poor riding may place the horse in a position so that he physically would find it extremely difficult to clear the obstacle (such as too far or too close to the jump).Additionally, riders who do not release over the fence, preventing the horse from stretching down, will hit the horse in the mouth with the bit and cause pain.If this happens frequently, the horse will associate the pain with the jumping effort itself, and may begin to refuse.