Hi Lorraine. I believe there could be two different causes for this problem. First determine if the rear legs are straight or crooked. Since many gaited horses are somewhat cow-hocked you need to consider that in your evaluation. From the front and the back of the horse, you may need to be off to each side slightly depending how the horse stands, see if you can draw a straight line through the stifle, hock and hoof. If you cannot the leg is crooked and it is a conformation fault. I do not know anything you can do for it. If you can draw the straight line the leg is straight even if it may be turned out when you look at it. For this there are exercises you can do to attempt to improve the twisting.
There is a ground exercise placing the toe of the rear leg on the ground behind the horse and then working at the stifle and hock. Place one hand inside the hock and hold it steady. Place the other hand on the stifle and do a quick push inward. Repeat two or three times on each leg everyday for six weeks.
Then untrack the hindquarters both on the ground and in the saddle. The inside leg will step under, the outside leg will step outside the body. Become accustom to doing this often anytime you are with the horse and every time you are with the horse.
Thanks for the info. I think we may have discovered her issue. Grass. Since we suspected an ulcer about two years ago, we have had her on minimal turnout to keep her moving and not stressed. I've kept a journal of our issues with her, different farriers, vets, ultrasounds, living environments, feed, supplements, etc.. Could not find anything that seemed to make a difference. About three weeks ago I was reading it. That's what it became apparent. She seemed to do the best during times she was on a dry lot. It's only been two weeks and she's a different horse. She's moving much more freely, muscles don't seem tight, the hock wringing and the tail issue aren't gone completely but are much better. Vet will be out next week. It will be interesting to see what he has to say. I've always described her as being laminitic like without full blown laminitis. Something in the sugars of the grass causes her tight muscles and just overall she would look painful. Vet had said whole body arthritis. She's now off everything completely except hay and water and after her blood tests,we might back down the pain med. Best of all her Brio is back.