Well, since you did post this in the horse conformation critique, I worry that the landings weren't videoed because he was having problems there. On a few of the brief videos, it seemed that he had trouble bringing his right hind forward to canter off. Is he totally sound? I am worried that he doesn't seem to be.
That's what I see, Allison, but I don't know enough about jumping to make an accurate judgment between what is normal, what is caused by lack of skill, and what is caused by unsoundness. But on the clips where the landing was shown, he looked uncomfortable and disengaged to me.
Luby, you absolutely, positively do not know that for a fact. He stands and moves like a horse in pain. You've had exactly one vet look at him, and it wasn't the most thorough of examinations. I know we've been through this a hundred and one times, but until he is thoroughly vetted by an actual lameness specialist, who knows far more about this sort of thing than the average equine/general veterinarian, I'm going to continue to believe what my eyes are telling me. Imagine if your own back looked like that....do you think it would feel good? I have a mild case of lordosis in my lower back, which is basically the reverse of a roach, and I am always in some pain, and it wrecks my posture and makes me a very stiff and defensive mover....
OP, all I can tell you is that he is not stepping forward after landing as I would see in most horses. He seems to be pulling himself along and not reengaging his haunch afterwards. I am not suggesting what is causing it. Only saying it is not normal movement, IME.
Compare the size of the jump to the horse & rider. If that is a 3'6" jump, then the rider has a future in the WNBA.
I don't understand why you're questioning this, it clearly shows it's below his butt, and cowboy is about 16h, and that would be around 3ft-4ft. And the white jump right next to it is about 2'6" Those white standards have measurements written on them.