Beginning trot poles.
The natural length of your horse’s step this is, usually, between 4 feet and 5 feet, but this varies depending on your horse or ponies height. When you introduce, the ground poles do your best to set them to match your horse’s natural step. You might need some help on the ground to accomplish this but once you figure out the distance, measure it and memorize it and use it for future reference.
Begin this exercise by breaking it down to the most simple elements. The goal in the beginning is to introduce your horse to the trot poles. Do not start by trying to get your horse to change the length of his/her step. Let them have an opportunity to figure out where to put their feet without having to edit their stride. Figure out your horses natural step and if your horse has a 4-foot step then set your poles 4 feet apart.
If you or your horse have never worked through trot poles, then walk through poles until you are confident. Set your goal to keep your horse going forward through the poles. Another option is to set one pole out for your horse to step over then add a second pole continuing to add poles until you have four to five poles in place. The addition of poles does not have to happen all in one day. Depending on your and your horses experience, add poles accordingly. Take as much time as you need to get four poles in place.
When you have your poles in place, and you have ridden your horse through the poles at the walk. Pick you your working trot and start using your half halts through the corners to get your horse attentive, forward and soft in the bridle. Riding through the corners use your eyes to find your path. Try to keep looking in the direction you are going, using your eyes to define your path. Before you begin turning half halt your horse if necessary, then continue around the corner. Try to keep your horse balanced and bent in the direction you are heading. When you come down the long side approaching the ground poles, half halt if necessary, to help your horse remain balanced, try not to speed up while keeping your horse straight through the middle of the poles.
When you ride through the ground poles, make sure to allow your horse to adjust his step and feel the swing in your horse’s stride. Adjust your hips and try to be soft and accommodating to your horse’s step. Try to keep your upper body tall and centered over your hips and keep your hands, and arms supple following your horse’s mouth. Avoid pulling or gripping with your hands or legs. If your horse speeds up through the ground poles then make your adjustment in the arena where there are no poles and enforce the halt-halt and as you approach the ground poles. When you gain confidence, continue riding the ground poles in both directions changing rein through the diagonals.
Trot poles require more energy than simply trotting, and you want this exercise to be fun for your horse. Give your horse frequent breathers and quit while you are ahead. You are much better off working through any exercise accurately then excessively.