Darn it, I knew that you were going to log on before I felt energetic enough to type anything...
There's also a minor thing that happens to my knees (and my muscles at times, hmm.) Sometimes, whenever I run, my knee just totally acts strange and makes it hurt to run. My muscles also pull a little at the strangest of times. Of course, neither are as bad as your incidents, but they're super-nagging. I hope it doesn't persist throughout my life. [And I also hope that something totally random fixes your problem. xD]