They are really one of the mildest signs that your horse had worked a bit more than they are used to. I've never had to much trouble with them and my horse never went lame, but I did notice them, fret a bit, poked, prodded, and then forgot they were there until I pick her hoof. It's not always your fault, if the horse was enjoying the work and he wasn't feeling any pain, he had no indication that he was taxing himself either, so you were probably never signaled by your horse to ease up a bit. They are just a natural reaction we use as a signal that to much stress is being put on the joint. Hard footing can be an equal culprit, so it could be what your riding on, not just how much. Don't canter on hard trails, and don't lunge in small circles for hours. Otherwise just keep an eye on them.
Troubled TB ~"A thorn by any other name will prick just as deep." @-'--,---