quote:
Not only that the effect of changing the foot structure from a flat footed splayed toed eohippus to the single toed equus also involves standing the foot up on the tip of the toe and using each of the bones between the tip and the heel to effectively make the leg longer for faster running while also making it more flexible than just adding length to the bones of the leg. Probably useful for getting through tight spots and to keep from tripping ... it certainly helps horses jumping in shows from hitting that top bar.
Mostly, I think the elongated, structure of the leg is for efficient speed.
Really, much of the horse's physiology has evolved for running.
Here is an interesting article about it:
source
A horse’s body is like a huge bellows, McKeever explained. Its breathing is dictated by the movement of its body and is in synchrony with its stride. Horses can inhale only when their front hooves are striding outward, they exhale only when all four legs come together -- the in and out of the bellows.
Unlike human runners who can take a deep breath independent of their leg movements, horses cannot take that extra-deep gulp of air when in full gallop, said Lawrence R. Soma, professor of anesthesia and clinical pharmacology at the University of Pennsylvania School of Veterinary Medicine. That means a horse with a longer stride has more time to inhale and exhale, allowing the horse time to breathe more deeply. Horses cannot increase their breathing rate without running faster or shortening their strides.
The horse with the longer stride has an advantage, because it has more breathing time, Birks said.
Edited by schrafinator, : No reason given.
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