Any horse owner who tours the medieval gallery at a museum must stop at the displays of suits of armor and marvel. Imagine the sheer weight of such an outfit–then imagine trying to maneuver oneself into the saddle wearing it! Visions of metal-sheathed knights being lowered by crude cranes and slings onto their groaning draft horses might in fact be hyperbole since historians say knights usually managed to mount without extreme methods of assistance, but the burden borne by a noble warhorse of the 14th Century must still have been staggering. And it begs the question: How much weight can a horse carry?

Those who study equine anatomy and physiology agree that if you really want an animal that's built to be ridden, you'd be better off seeking a camel than a horse. Even a cow would be a more logical choice, from the point of view of its vertebral construction–it has interlocking lumbar spinal articulations which, in theory, make it capable of bearing considerable loads (although its suitability as a riding animal can be questioned in a number of other ways!). The equine spine lacks these strength-lending links, and with its suspension-bridge construction, the horse's back is actually rather poorly designed for weight-bearing