If you take notice to the picture link of the very last horse youll notice there is no chains used- you can't use them in the ring anymore- another thing for the better that has been changed.
The picture of the horse standing under itself is an old picture from 2009 or around that time- weird thing- my horse stood exactly like that today and she is not sored padded or shod at all- has no health issues- not ever foundered and I just done her feet yesterday- definitely not in any kind of pain at all- I spun her in a tight circle like I would a quarter horse and that's what happened- it was pretty close to our gelding and she is very submissive and balled herself up because she thought she was too close to him.
I have seen the videos of them rocking and that could be pain or could be a behavior from being stalled up just like cribbing or stall weaving or walking.
I don't think the pads if done right cause any harm to the horse- if you look at the action its the same with out- the pads just add weight and make a more animated gait- they still walk the exact same way-- I don't think its abuse when a woman is in stilettos - maybe if her dh pored caustic chemicals on her ankles and made her wear chains- that's a whole nother argument though. I think of pads more like the big comfy beach clog hoppers though- its that type material and theyre even strapped up the same way.