Also folks, please do not equate putting a chain around your ankle or wrist to a show horse wearing one around its pastern. The anatomy is totally different. The pastern is the same bone as your finger bone and the front of it has the same amount of padding between the skin and bone as the top of your finger bone, which is essentially none. Try lightly tapping the top of your finger with a plain number 2 pencil and see how long it takes for it start huring. Not a perfect equivalent I know but the best I can think of.
Actually, by tapping, you are exerting an outside force other than gravity to it. By tapping, the force is increased and thus pain is increased. There is nothing but gravity acting on the chains. Movement yes, but not enough to cause direct harm, unless the horse slams his foot to the ground. To be more accurate, you should drop the subject onto your finger.
Tapping your finger with a pencil, you sure as heck can sting your finger, especially if you are trying to prove to yourself that you can hurt yourself. Tapping is the equivalent of taking a thin broomstick and tapping your horse's leg. You are exerting more physical force than gravity alone. And you know what, they will lift their leg to that kind of pain. My friend had her QH trimmed with one guy. Horse wouldn't pick up his foot, so the farrier took his rasp and tapped him on the fetlock, he picked his foot right up. Farrier hasn't been back to trim that horse. Try tapping a horse's leg a speed to make them pick his feet up... if you have much success with that, you are a much nimbler person than I. Quicker to to be able to keep up with a horse at higher than a walk.
I must say that the panic thing is a new one for me. I actually laughed out loud when I read that. If that were the case, if they thought they were trapped, being attacked, or their prey response was somehow triggered, they would not simply be lifting their leg higher. If they were truly in panic they would balk, they would run, their brain would fall out of their left ear, and they would be in a pure reactive state. I have seen horse's panic.
They do not respond like that to something they think they need to step out of. If they did, they could not walk through mud, or high grass, or snow, etc. without panicking after a few steps, or if it were mental stress, they couldn't walk through these things without experiencing similar mental stress as you claim they are experiencing.
My mare has panic attacks over her head. She throws herself over backwards, she runs, she fights, she tries to escape. I have never once seen a horse panic over chains. A halter causes my mare much stress. Care must be taken when leading her for your own safety. Luckily, she is not going anywhere, and no one but those who know how to handle my wretch will do so. She's quite happy in our field.
It is the horse that chooses to respond to the chains. It is not the chains which illicit a response. If I were to put a pair of standard training chains on my sister's QH, I would bet anything he wouldn't respond to them. I would bet my Saddlebred's tail that he won't and I have never put any on him. He is not built to trot much higher than the width of a corn cob. No amount of anything will make him trot higher than he is built to do. And he is not a very reactive horse. There is nothing I can do. He is what he is and a show horse he'll never be. I could try to make him one, but I will fail, I won't be happy, and he won't be happy, and it will be a worthless waste of time.
As for pressure shoeing Saddlebreds. Um, no. There is no division for Saddlebreds which does not require a horse to trot. A Saddlebred with unsoundness issues, or soreness issues will not trot square, and he will not pick his feet up higher than he must. Pressure shoeing is counter productive with a trotting horse. We have had many horses come to us with unsoundness issues to fix. The unsoundesses must be fixed before that horse can perform at any level. Being sore is an unsoundness. My father is a trainer and farrier, exclusively to Saddlebreds. My brother is a farrier exclusively to Saddlebreds. Both of my sisters work for top show barns. I have been working with the breed for many years. My life is devoted to the bred. I attend many shows from the county fairs to the World Championships. I attend as many functions as I can. I am not shy about asking questions to ANYONE. I talk to trainers. I talk to farriers. I talk to breeders. I breed and train my own specimens. I am currently working ten individuals all in various stages of training and who have different suitabilities. I do know what I am talking about from years of study and hands on experience with all aspects of the breed. Whether you believe me or not is up to you, but I have proof, I have evidence, I have experience to back up all of my claims.
There are many issues I have within my breed, but this issue is not one of them. There are some issues that make me even angrier than dealing with a person who has never experienced the breed making untrue claims about them. Soring is not one of those issues. I will stand by that until hell freezes over, or until my breed is extinct. We have plenty of real issues without having to defend them from untrue claims spoken without knowledge.