Injured at class

I knew it would happen eventually. She loves to "dangle" from my arms and swing...and she often tries to plop down when I hold her hand to cross the street, which results in being dragged a few seconds before we can readjust. I didn't think it would happen at music class.
We were playing a game all holding hands in a circle when she tripped (or lunged maybe, I don't really know!). There was a crackle in her arm and a few seconds before the scream. I knew what had happened right away, so we were able to go to the side of the class and get ourselves pulled together. She wouldn't let go of her arm and she was very upset. SHe wouldn't move her arm at all from the elbow down. I moved it a little, thought it snapped back, but she was still loudly upset.
So, of course, we called the doctor, who said to come right in. Of course, by the time we got there, it was better. But, she taught me how to fix it, not if, but WHEN it happens again! UGH!