I was at karate and we were practicing assorted double kicks. (Roundhouse --> spinning hook, roundhouse - hook). I wasn't doing great, but my partner was nice. Then we got to "start as a front kick but after the chamber change to a roundhouse". I did it a few times and then my right leg felt weird. We switched and she did it several times while I was wondering about my leg. We switched back. I did it one more time and it was a mistake. My whole leg went slightly numb. Not as bad as when a leg falls asleep, but enough that I needed to stop. Within about fifteen minutes there was just a ghost numbness - it might have been my brain over-feeling by that point.
In any case, it was rather weird. I've never had my leg suddenly go numb like that. It was a bad night for injuries - real and imagined. There were only 12 students and three went off the floor at some point for assorted reasons. Usually we can go weeks without any injuries.