khall wrote:Tsavo in the case of foals with acquired club foot it is because they have a short usually higher set neck and long legs
And a short head, as some foals can make up for the long legs and short necks with a longer head.

But AFAIK, there was one graduate thesis that came up with this theory and it did not include measurements, or follow up, or confirmation of any kind. There may be more now?
This is my Luso filly shortly after she was born, she was all legs with high set neck from her Lusitano side. She quickly adopted the split legged stance for grazing once she became interested in eating grass. In the research I did after she had to have her check ligament cut, I found it is recommended to turn them out into rolling hills with longer grass so they do not have to adopt such an extreme stance.
I found that I can turn mine out into lush pasture with all kinds of tall grass that would be easy to reach, but Mr. Club still goes into the stance so he can reach the short (tender/higher sugar?) grass. So I soon abandoned the whole idea of turnout when he was still growing, because it was obvious that he was going to be spending a lot of time in the stance if I left him on pasture. He still, at 13, goes into the stance any time he wants to reach the ground. But at this point I feel like I've done what I can, his skeleton is what it is, and his club seems to be grade 1 and stable.
.BTW the Arab I cared for with grade 3 club foot ALWAYS had this extreme split legged stance. So it is the high set neck and long legs of some foals that lead to the adopted grazing stance. My foal was not lame until much later after the club developed to the point requiring surgery. No shoulder injury ever. Neither of my foals had shoulder injury, the WB filly now 9 did have epiphysis that required me to back off on big TO and reduce her dam's grain to slow the filly's growth at the time she wore the cuff/wedge.
I think this is why we still don't know what causes a club to develop, because there may be multiple causes, or hidden causes, or unknowable causes. My horse could have sustained a shoulder injury at birth, or have been more crowded in the uterus than other foals (so curved more), or could have had a shoulder injury that was mild enough so that there were no observable signs? He does fall into the long leg/short head and neck category, but that may just have caused the club to develop more, or faster--or have had no effect? He was never lame and I never saw any marks on him before I noticed the clubby front, so who knows?
This extreme stance due to short neck and long legs. I also read research where in the WBs today they are seeing much more of high/low feet issues because of the high set necks and long legs being bred. I know my old line Han have much shorter legs than what is being bred today.
I think it's common in TB's too, which is possibly because of the same kind of conformation, or maybe just because there are so many of them?
When I bought my WB I didn't even think about looking for something like a club foot, because I was under the mistaken impression that they were genetic, and I figured that all the inspections would have weeded them out of such horses. But now that I've become more tuned into one up/one down and club feet, I see plenty of them in WB's (along with all kinds of other problems that I would never have thought would crop up in horses that had to be inspected before they could be registered).