Q. I take riding lessons, and when I try jumping on one particular horse, he usually runs out. What can I do?
A. First and foremost, do as your riding teacher instructs in this situation. (S)he is the only one who knows both you and the horse and sees exactly what’s happening in your approach to the fences.
Running out can be caused by a number of different factors, each one requiring a different remedy. It’s possible the horse in question is just tired, sour, or lazy (a common affliction among school horses), in which case it may be necessary to use considerably more leg or perhaps even a tap with a crop before the jump. He could also be sore, in which case he shouldn’t be being jumped at all.
It’s also very possible that this animal may be particularly sensitive to his rider’s weight distribution in the saddle and application of the aids. Is this horse consistently running out on the same side? If so, check again for any physical malady on his part, but also check to make absolutely certain you are not leaning, even the slightest bit, to the side of the runout. Even the smallest increase in weight in a particular stirrup may prompt a runout on that side. If you are leaning significantly off balance to one side, a runout in the opposite direction may even be promoted.
Check also what you are doing with your aids in the approach. Are you maintaining steady and equal contact with both hands and legs, or is there a possibility you are actually cueing your horse to runout by emphasizing cues on one side of his body? If you are poorly balanced or inconsistent in your application of the aids in the approach to the jump, he may just not have enough confidence in you to proceed over the jump.
You might want to discuss with your instructor the possibility of lowering fences with this horse, perhaps easy cross-rails that help direct the horse visually toward the center of the fence, and adding a few ground poles in the approach to focus the horse’s attention on maintaining a steady, energetic trotting stride right up to the jump. Using 2 more poles resting on top of the standards/wings and angling to the ground in the direction of the approach will create a chute which makes runouts far more difficult for the horse, although he may substitute stopping for running out at that point.
Do talk all of this over with your instructor. It is likely (s)he will have a much clearer perspective on the cause of your trouble with this one horse.