let us return for a moment to that time less than 2,400 years ago, of the IV century BC, when Athenian hippeis, adventurer, philosopher and writer Xenophon (Ξενοφῶν ) wrote his famous On Horsemanship ( Peri hippikés) treatise, and I am going to 'publish' here the most relevant parts of that ancient work since this work seems to sum up the ancient Indo-European (North Iranian, Thracian, Greek, Persian and Median) knowledge on horses in war and parade.
Xenophon (Ksenofont, Ксенофонт,) :
1.In regard to a colt not yet broken, it is plain that we must examine his body ; for of his temper a horse that has never been mounted can give no certain indications.
4. Since we have commenced with this part, we shall ascend from it to the rest of the body. The bones immediately above the hoofs, then, and below the fetlocks, must be neither too upright, like those of a goat (for then, being too unyielding, they shake the rider, and such legs are more subject to inflammation), nor ought those bones to be too sloping; for the fetlocks will in that case be denuded of hair and galled, if the horse be ridden either among clods or over stones.
link to a Spanish language scholarly article (from Gladius magazine) on the Ancient Greek riders and their 'echo' amongst the Iberians http://gladius.revistas.csic.es/index.php/gladius/article/download/29/30
at the top my own little sketch of a warhorse, I hope :) and a photo of a Hellenistic spirited war horse covered with a leopard 'schabraque' (sort of like Alexander the Great before and Hungarian, Polish and Ottoman Turkish riders during the XVI-XVIII centuries)