Now let’s look at hind limb construction  from the hip down to the foot, and see how it works.
The horse’s pelvic length is measured from the hip joint to the point of the buttock. The larger the pelvis is, the larger can be the propulsive musculature and the more power the horse can produce. An old rule of thumb in conformation judging is that you should be able to divide the horse into thirds. The front one-third is from the point of the shoulder back to the elbow and withers; the back from the withers to the point of the hip another one-third, and from the point of hip to point of buttock is the other one-third. A horse with less than one-third of his body length in the pelvic area won’t have the power to push the longer lower hind limbs under the horse as far or as easily as one with greater length and musculature. We also need to look at the pelvic slope. It should be moderately sloped, not tending toward flat, or the horse will “leave his hocks behind” as he travels, again not allowing our walker to stride up under himself.                                                                                                                                              
The next area to look at is the femur, or thighbone. This is an extremely important link in the hind leg assembly. Think of the hind leg as a series of rod like links. First the femur, then the gaskin bone, then the cannon bone and pasterns. If these bones were hanging by themselves and set swinging, they would behave like a chain pendulum in which whatever the uppermost governing link does the rest of the links follow in the same manner. A long first link, or femur would therefore set the leg in the slower, longer swing. This is part of what can give the walking horse the long slow ground covering stride that we all appreciate. This does not mean that a walking horse with lesser length of the femur won’t gait, but it will be a shorter more rapid stride suitable for rougher riding or ranch work. Shorter femurs are desirable in trotting horses that are used in speed events or sprint racing. In a sprinter, long hind limbs prevent the thrust generated by the rump muscles from being delivered to the ground and is a disadvantage. Having a longer femur gives the walking horse longer hamstring muscles which should tie in low to the Achilles tendon. In a profile view of the rear legs, the hamstring muscles should flow down, making that part of the leg appear long. If it appears rounded and the notch in the profile from buttocks to hocks is deeply indented, he ties on high, the femur is short and so is the hamstring muscle. This will limit the forward movement of the hind leg.

The next link on the chain is the gaskin bone and muscle. The pelvic and femur length is often hard to see because of the muscles of the rear quarters, but the gaskin length is easy to see. This is the bone from the stifle to the hock. Most walkers have longer gaskins. However, we need to remember that if the femur isn’t also long, the swinging leg pendulum won’t produce the long slow stride we desire. If rightly proportioned, the longer gaskin and the long femur are desirable in our walkers. A long gaskin in most trotters is a disadvantage, some exceptions being horses used for dressage requiring extension of rear legs and saddlebreds. Walkers being used as trail horses in rough terrain or working ranch horses won’t find a very long gaskin of benefit. These horses will do better having a gaskin and femur more near equal in length. Ideally, in the trotting pleasure horse, the femur is longer than the gaskin in length.

Next is the cannon bone. This bone should be short, so the horse’s hocks are close to the ground. High hocks predispose the horse to “travel downhill” especially if they are quite a bit higher than his knees and he will have trouble getting his hocks up under himself, a very important thing to remember with our running walk. A good way to judge the length of cannon bone length is to compare it with the front cannon length. The hock should appear only a little higher than the knee. In the front leg, the upper arm should be longer than the cannon. It is considered good conformation to have low hocks in any riding horse. In a visit to a standardbred training facility, I noticed that the pacers had gaskins longer or equal in length to long femurs; but in all the ones I saw, the hocks were set high, with relatively long cannon bones. It makes sense when you remember that for racing the pacers need a fast swinging of the hind legs, easier when the leg below the femur is more equally divided in length. This is not the long slow sweeping stride we desire in the walking horse.                                                                                                                                       
In review of the Tennessee walker’s long hind limb conformation, we see that the most correct way is to have one third of the horse’s body length in pelvic length for power with a moderate slope, a long femur with it’s accompanying long thigh and hamstring muscles to provide the long slow swing of his leg pendulum, a moderately long gaskin to give more overreach and short cannon bones enabling him to set his hocks under himself.
This gelding has a fairly nice shoulder. The length of the humerus is not quite as long as some of the other horses to be shown, but it is adequate. (shoulder conformation discussed later) His problems are all in the rear third. He is extremely straight legged for a walker. His hind legs are actually type #2 with nearly all his leg in front of a line drawn from his buttocks to the ground, yet he does not stand excessively rump high as would a longer legged walking horse when stood in this same position. His stifle is almost dirrectly below his hip. His exceptionally straight legs put strain on the stifle joints and he does have stifle problems. His pelvis is short. He actually does a 4 beat flat walk, with about a 4 inch overstride, but he cannot do it with any speed. When he goes faster he sort of makes up his own gait. This horse is a good example of a horse being able to stride in front only as far as his hind quarters are capable of pushing him.