From About.com:
Underlying the stifle area is the stifle joint formed between the large hip bone (femur) which is equivalent to our thigh bone and the tibia, equivalent to our shin bone. The stifle joint somewhat resembles a human knee.
it is in the middle of there back legs it would be like a knee on us but its called a hock
It's on a horse's back leg about the same height off the ground as his knee is.
The joint between the horse's hock and hip is called the Stifle joint.
this long bone that runs from the hock to the fetlock is called the cannon bone
They are called hock boots and they are worn to protect th horses leg when jumping.
A horses leg is called a leg, but it has several names for different areas of the leg like cannon, hock and gaskin.
Mike Hock
It is called a capped hock. A horse's hock is the same as a human ankle. Most likely if your horse has a large bump on the top of its hock, it has been injured in some way. On a horse that has not been injured there should be what appears as a small bump on the back of their hock, this is called the point of the hock. I would suggest consulting your vet about any bumps you find on the front of a horse's hock.
Chestnut applies to horses in two ways; one is the color, which is reddish brown. Another is the bony protrusion from above the horses knee in the front, and from the inner hock on the back. This is in no way harmful to horses, it is present on all horses.
Horses have two knees, one on each foreleg. The equivalent joint in the hindlegs is called the hock.
It depends on wich part you are talking about. there are three. The feltlock, the pastern, and the ergot.
For a young horses' joints to fully fuse, it takes 3-5 years. This is why horse racing is very dangerous because the horses are not fully developed. Do not jump/race/work hard with immature horses!
That is for me to know and for you to find out.
Because there is no muscle below the knee/hock to cushion the bones