Can you explain more on the artificial way the farrier trimmed the backs? Isn't this actually the bottom line of your issues, nothing to do with working from behind and dressage, but simply an unbalanced artificially shaped hoof that's gone on for a such a long time, it's now caused all the tightness and the horse is off balance?
Any farrier or trimmer using whatever method should shape the hoof to the shape the hoof is, never alter the natural shape. You do not need to be touching an unshod hoof every six weeks and if the farrier has found something to fiddle with, he's been taking off foot that Ben has needed.
My lass has one hoof that's slightly bigger than her other, it grows slightly different. We never force that hoof to match the other one.
If he's arthritic he might stay 1/10 lame. I don't follow the need for a gait analysis to be honest. You can film him yourself and slow it down to show the gait. Unless I am missing something. His backs need time to adjust to be allowed to grow as they need to.
I don't want to be at the stage where mine hasn't seen the farrier for three years. If your horse goes lame the first thing the insurance company and vet ask is when did you see the farrier. I like my farrier to pop out and look her over, level if necessary. I am not a farrier and I still value his professional input.
I have parted company with the farrier who trimmed his hind feet so can't really discuss his approach. To be honest I just let him get on with it with the view that he was a professional and was doing a good job. Yes, his stifle injury could have been caused by an incorrect trim which left his feet too boxy and upright. Or, this could be his natural confirmation and it would have happened anyway. Or it could have been the dressage that caused the stifle injury which caused him to move in a certain way which resulted in his hind feet becoming too boxy. I never used to speak to my farrier and I had no idea that his feet were not in a good way. If I had, perhaps the lameness would have been avoided?
The plan now is to leave the feet well alone and see what natural shape they fall into. My farrier and vet are working together to closely monitor him. The aim isn't to suddenly ditch the farrier, it is a case of working with him to achieve the desired outcome, which is a completely sound horse.
The gait analysis is part of a barefoot clinic I am going to which is being run by Rockley Farm. This will look at exactly how he lands on his feet at the moment which may provide some answers regarding his lameness.
For me, the result will not be what his feet looks like or what shape they are, it will be in how he moves. If we can shake off the remaining lameness and get him moving better, that is what success looks like. I have no idea if it will work or not, I am not saying that the self-trimming method is the only way for barefoot. All I am saying is that this is the path I have chosen to take for now. I respect all the different methods of feet care and I appreciate that this may not work out and we may be back in shoes within the month. But if I don't try, I won't know.