Heel.
Yes, really, the heel. Turns out that when I cleaned up Sean’s and Daniel’s room after they broke the light bulb in the dresser lamp, I wound up with a tiny shard of glass stuck in my right heel. Obviously, I didn’t know about it. It took over a week, but it finally got worked into the callus enough that it was causing pain when I stood or walked on it. My body naturally compensated by lifting the heel while standing or walking, but then that threw my right knee and left lower back out of whack.
I finally saw the doctor yesterday, not knowing what the source of the pain was. There was just a small bump on the heel. He was able to extract the tiny sliver of glass, and everything feels great now.
And not to start on my rant yet, but think about this — if that had been a fluorescent lamp, I’d have pumped a little extra mercury into my bloodstream with that shard of glass (too small to see during the clean up).