Gayle Trotter, DVM, MS, Dipl. ACVS, a professor of clinical sciences at Colorado State University's College of Veterinary Medicine and Biomedical Sciences in Fort Collins, holds a moderate viewpoint on the subject. In other words, excellence in performance gave rise to the establishment of physical attributes as desirable in achieving that performance. I look at the way his limbs move and the quality of his gait. Stiff, stilted action, which may or may not result from 'post-legged,' upright conformation, generally is not good in terms of athleticism.
Athletic performance is just part of the equine-suitability equation.
The other part is the horse's ability to withstand the athletic demands placed on him. Most people don't want to buy an unsound horse, nor do they want to buy a horse which they believe is likely to become unsound. Again, conformation traditionally has been viewed as an indicator of the potential of such possibilities. We'll look at each defect and explain why it might predispose a horse to physical difficulties, with the caveat that every veterinarian knows of horses whose conformation is a textbook example of terrible, yet who have led sound and productive lives. Straight hind legs .