Horse plaiting??? conformation?

Ah, my gelding used to move like this. He was very locked and stiff in the haunches and back. Once I did more loosening work like cavalettis, trot poles, long & low, trail riding, his trot got more forwards and dressage-y. However, this was after corrective trimming- he had splayed hooves when he plaited, but like I said, he moves freer and much more beautifully now. Yes, it is fixable. And MAYBE it could be his hooves.