Feel very free to ignore me. This is only my opinion and its not worth much at the best of times!
I've always found his posture concerning but based solely on the two pictures provided I would engage the services of a very good equine vet and my thoughts are that there might be something needing addressed but obviously just a discussion with them initially.
If a plumb line is dropped down through the seat bone and hock the hindlimb in the "after" picture is further in front of it and it appears the the fetlocks have dropped. With the disclaimer that the photos aren't taken at the exact same angle in the exact same location etc
The negative plantar angles are obviously a concern but nothing happens in isolation and I'd want higher up looked at too, be it as a primary or secondary issue.
The forelimb stance, and shoulder, appear to have changed angles too although it's hard to see clearly with the boots on if that's hoof or what related.
Its evident he's recently been clipped and has just finished work but the marks left by the saddlecloth/saddle are deeper over the withers and at the front of the saddle. The highest pressure area is generally where the rider sitsbut shouldn't be where it looks like in the photo. He has clearly filled out behind his wither but I think the saddle may need checked and adjusted to allow for that.
No help with the hooves as I'd pull shoes and xray then "rehab" a horse barefoot to let them, within reason, sort themselves rather than in alignment with how a textbook says that they should look and move.
Iirc, and every chance I don't, HufflyPuff had a similar horse that she massively improved with posture training and rehab type groundwork.
@sbloom has a list of good resources for that type of work too.
I hope that I'm very wrong and it's just bad photo angles. None of my business but you asked and that would be my answer not that it's worth a jot as a stranger on the Internet.
