Could this be my trotters stifles?

Hi thank you for the nice comments. Our horse Moms super boy is racing Fri In the 3rd race he has the 7 hole at Saratoga. Wish us luck. I trained him today and he was really sharp.

Stifles

Sounds like you figured this out but I had a similar issue with a dressage horse. He was fine on circles but on straight aways he got strung out. He just had difficulty doing the work. The horse was a great mover but had trouble in transitions, etc. We did all kinds of diagnostics including x-raying his back, everything came out ok. His stifles were a little loose though especially after I pulled his hind shoes. We fixed the issue with putting heavier shoes on behind (the shoes were like little weights that added muscle to his stifle area so when I pulled them things got progressively worse) and doing hill work. I just have a little hill behind the barn and I rode him up and down it every day. After all this time and money of trying to figure it out he is now athletic and willing…