OP, I am not knowledgeable enough to give you advice in a show bred TWH movement. But, I will tell many of these posters that there is a huge difference in the haunch movement of a TWH than any other breed of horse who doesn't have this gaited action. I have seen TWH show horses that have very similar action. They have a weird ability to step WAY under themselves that makes them look very "wonky"
Since you bought him from a show barn, was he ever anything but flat shod? Even flat, they will exhibit very different movement than other horses.
The horse in this video is totally sound. However, not being familiar with TWH, he looks odd to me.
Before you post on a thread, make sure you know what you are talking about AND, if you feel that you disagree, do it NICELY. It really is not that hard!!
Diego, I am so sorry your reception here was so hostile. There really are nice and helpful people on this forum.
Do get a vet who understands TWH to check him out. Then, come back and let us know what they find out.