So let me start off by saying that I am pretty good at telling if there is something off with a horse- whether it is feeling it or seeing it.
However, when it comes to pinpointing exactly which leg, I usually haven't got a clue. All I know is something doesn't look right or feel right. I just can't pinpoint exactly WHERE.
For example, someone would go "she is off in her left hind"
I'd be able to tell something off, but how on earth they figured it out it was their left hind is beyond me.