Why do people use a neck stretcher?

Hello. I cannot say why those particular horses are worked in a neck stretcher. If it is at your riding school, I think you should ask your instructor.

My own view of the neck stretcher is that, like many other training aids, it is more of a hindrance than a help. For the horse there is no logic in something elastic. It may have an effect there and then, but the horse most likely learns to push against the neck stretcher, or to drop its head right down. The result is that, without it, the horse still rushes around with its head too high, which is often the very reason the neck stretcher was fitted in the first place.

What you want the horse to learn is to lengthen its neck without leaning on the bit, and that takes schooling by skilled riders, so that a rider who is still learning can get a good feel for it without any fuss. On top of that, the neck stretcher misses the most important point, that both the forward thrust and the collection must come from behind. Adding pressure in the mouth to create bend or lengthening in the neck tends to give the opposite effect.

I hope that answers your question!