This is my client Liz’s pony, Kazan, who doesn’t have the biggest stride (he’s only 14hh), and tends to move a little flat.
He’s a careful chap though, so I used poles to get him to pick his feet up, and improve the moment of suspension in the trot. In the photo you can see his improved knee action and him bending his hocks well.
To encourage him to lengthen his stride, I also set the distances slightly wider than I might normally do for him.
The result was great, even when I made it five poles in a row!