Oh, crap, I hope I didn't pull anything ...
Then I had a look and realized that the sore spot had nothing to do with dropping the little 'un onto the cushions, but was a residual effect of the most recent silat class, wherein Edwin, doing the outside high-stab defense, kept punching me. We must have done that thirty or forty times, at least. And he does not want for accuracy, hitting the same place every time.
Ache explained, and no big deal.
Sometimes don't notice these kinds of low-grade injuries for a day or two, and then have a moment of wonder as I shuffle through the memories to see if I can find the cause: What did I do?
Oh, that Edwin. Beating up on a poor old man like me. It's a shame, really it is.