If you like to read breed standards, or simply want to understand them better, you may have come across the phrase, “hocks well let down.” What on earth does that really mean?
The “quickie” (and very simplistic) explanation that the hock is a joint the same way your elbow, ankle or knee are joints. It forms the junction between two bones (the tibia and fibula) and several bones that make up the area called the “pastern.” For now, forget the pastern.
The term, “well let down” is another way of saying that the hock joint is close to the ground, or short in length. It’s felt that such hocks benefit breeds that are endurance trotters since they put less stress on the Achilles tendon and reduce the muscular effort needed to lift the dog’s weight. Short, or well let down hocks may sacrifice a dog’s initial burst of speed, but in the long run, 
literally, they are better for endurance. Is there such a thing as “high in hocks?” You bet. These dogs have longer hocks that offer greater jumping power and speed. Additional information on hocks can be found in any good book on canine structure, but this article also is also worth a read.
Thank you! This is in the Chow Chow standard. I got in an argument one time because a friend was upset her dog hadn’t done better at a show and when she questioned the judge he told her his hocks were too long (he was kind and didn’t mentioned they were cow hocked as well). Anyway, she was ranting over how he told her that and that it wasn’t anywhere in the standard that Chows should have short hocks. I looked at her and asked, “What exactly do you think ‘hocks well let down’ means?” She had no clue and had never asked.