As the boot went into the stirrup it obviously runs into the heel; the heels have two purposes. The first one is obviously to stop the boot from going straight through the stirrup. More importantly, way back when there was no pavement, no concrete or anything like that, so when the cowboys would dismount off their horses their heel typically was little bit taller. So they would dig it into the ground to allow them to get off their horse safely and have some sort of stability for the foot. The heel also had another purpose; it also held the spur in place. There is something called a spur edge or heel rand, which extended out from the actual heel part of the boot and it created somewhat of a shelf. So the spur was able to rest on top of that. So that helped keep the spur in place.
