Bio, Funny you wrote about this because I do have popping
in my knee
. It happens in particular with certain Tai Chi positions, but not all the time. I wrote about this in my journal about my first tai chi classes.
It goes away, but tonight it was back again. My knee is not strained, dislocated or otherwsie injured but it makes this very loud "pop, pop, pop" sound much like the popcorn your described. AND everyone in class can hear my knee going off!