Recently a client of mine has been shopping for a stallion for her mare and throughout her search I have been helping her look at each individual's conformation.
One stud in particular had a pretty extensive work history but also some pretty bowed hind legs, and the question came up as to whether it was his conformation or his work history that made him that way.
Questions like this always make me think of a old cowboy I've always admired growing up named Weldon.
You see Weldon was one of the last true cowboys (He is still living but finally stepped out of the saddle just south of 90 years old a few years ago). He worked cattle almost everyday for over 65 years. He rode his horses miles and miles everyday, hours and hours at a time, and did anything the job required.
I have never known anyone who has ridden more or ridden harder than Weldon. And despite his demanding schedule his horses were often still doing a full day's work up until their early-mid twenties and 9 times out of 10 they were still sound when he chose to retire them.
He had a type. Short (under 15h), huge hip, short back, short loin, big bone, good feet, good shoulder angle (for those 1,000's of trotted miles), and straight legs.
He knew that a well built horse could hold up to his line of work and do so fairly easily, and that poor conformation would lead to premature aging and injury.
At the end of the day most every horse can do most every job/discipline, but the right conformation will allow a horse to excel, age gracefully, and stay sound in that job/discipline for a lifetime.