Well, Im gonna do it anyway; if she wants me to take it down, I will. :-)
Wunderkind spent a lot of time putting together an article explaining, well, horses, basically, and the different breeds and roles. I thought it was a well-written, very informative piece of work, so I PMed her asking if I could post it; she hasnt answered yet, but I cant wait, lol. :wink:
Horses can survive a load of heavy injuries in the wild without even flinching, but they have one mega weak spot, and that is their legs. I've heard of horses loosing entire muscle groups and going on and living happy full lives, but they blow out a bone in their leg and it's all over. The reason is that the only thing their legs do is hold them up off the ground.
When I say horses are delicate, I'm not trying to say their not powerful. They are. A Fjord Pony can pull four times his own weight (that is to say, for the same about of wieght you hitch two Morgan Standards up to, you only need one Fjord). However, a horse's power is not in their legs, it's in their chest, back, shoulders, and thighs. If you take a good close look at a horse's leg you'll see there's not a whole lot of muscle there, it's mostly bone and ligament.
Rather gruesmose image of rear left leg damaged most likely by barbed wire. You can see how easy it is for a cut to reach the bone. You can also see how little muscle the legs possess.
(http://www.wildhorsespirit.org/Images/Blondie/7-10-98_Blondie_-closeup_leg_wound_-dog_29KB.jpg)
The legs of a horse don't actually have any strength of their own, but are powered by the shoulders and thighs, much like the pistons of your car engine. These large muscle groups of the back and shoulders are what provides all those romantic images in our heads of "rippling muscles" and "beautiful strength". A well rounded horse will have even strength in both the shoulders and the rear muscles and good strong back.
(http://ultimatehorsesite.com/images_colors/bloodmarks.JPG)
Like all vehicles, certain breeds (or brands) have certain attributes. If I want something very powerful that can haul heavy loads or work long hours, I have to look into the heavy duty classes. In the horse world, we call these classes "drafts". Draft horses have a huge amount of power and more muscles in their actual legs surrounding the leg bones. This allows them to be stronger in the long term although their muscle bound legs make them slower.
"Shire" Horses are the classic draft horse, originally bred to ride into battle at full speed carrying knights loaded with armor. While they are not remarkably intelligent, Shires are incredibly loyal,trusting, and diligent. They will run through a brick wall unless they are told to stop.
(http://www53.tok2.com/home2/bronco/Shire%20Draft%20Horse.jpg)
The more strength a horse has in their shoulder in relation to their rear the more flexible and more manuverable the animal will be. These horses make excellent "dressage" candidates due to their ability to turn sharply and swiftly and their potential for grace. These more "graceful" horses are often loyal, but will have a hard time following orders as they tend to think for themselves. Shoulder-strength horses are hard workers with a high endurance but delicate rear legs that can be twisted easily in a fall.
The essential "cowboy's horse" the Quarter has an immense amount of shoulder strength, making it the perfect horse for cutting and herding which requires a sure-footed, quick, manuverable mount with a high level of intelligence. The Quarter earned it's 'funny' name due it's ability to clear 1/4 miles in less than a minute. It is the drag racer of horses.
(http://www.livestockexpo.org/images/gallery/quarter_horse_show.jpg)
A horse that is fast, either in the sprint or the marathon is a horse that needs long, slender legs that can move quickly and powerful shoulder and rear muscles to move them. Behold the Thoroughbred:
(http://www.thebestlinks.com/images/e/e9/Thoroughbred.jpg)
It is joked by cowboys that a Thoroughbred is not a horse. It's a set of four legs given the brain of a woman.
Thoroughbreds were bred to race. From the very beginning the only thought that was put into them was speed. They are often high-strung and nervous natured. They are like hyper and competative children. Their fine bone structure means that they are light and quick, unfortunately it also means they are very breakable. Like Arabians, they are fast and capable of high-endurance speed, but should they step wrong or stumble, it will spell doom.
The sure-footed, high-endurance legacy of the Arabian has made it a creature of myth and lore. Unfortunately, this small desert racer does not have the size to clear the strides of the tall, lanky Thoroughbred and the two rarely compete against each other.
(http://www.probertencyclopaedia.com/j/Arabian%20Horse.jpg)
When the fine bones of a horses legs break, they splinter and shatter like glass. Even if they are reconstructed, the fractures will weaken the legs ability to uphold the massive amounts of weight demanded by the horse's bulk. Because the leg themselves do not have any major muscle groups, they do not have any power of their own, and their only strength is in the ligaments surrounding the bones, these ligaments are often torn or destroyed when the fragile bones break. Although reconstruction surgery is available, often it is complicated and the follow up procedures are long. The artistic work necessary is over shadowed by the immense pain that comes with the healing, and the healing may never come. Usually, in major breaks, the leg is unable to heal completely, since the horse cannot be banished to bed-rest like a human. They must be up-right, and even with a sling in place, sometimes, it just doesn't work out.
This picture shows the pins and braces required to correct a broken front ankle.
(http://www.twinpeaksgazette.com/community/uploads/23/image_3681656.jpg)
This may all seem very comprehensive, but it is only the tip of the iceberg. In fact, it's a chip in your iced tea, off the ice-berg. Since the anatomy of a horse controls its place in the world, it often has a huge affect on its behaviour as well, and how a person will train it, and interact with it.
It's a common mistake for someone to say, "She only slipped a little on the path, it can't possibly be that bad." Just remember that what might have been a little slip in your 180(something)lb eyes, was actually, a 1500(something)lb slip and the damage increases in relation to the mass.
Food for thought.
By the way, this is my subject. This is where I am most comfortable, so if you have any other curiosities, I'm more than happy to answer and explain. :-D