Thanks for your concern but it is really not too bad an issue. I had a knee problem that still bothers me but is largely healed after a decade or so. Now I probably should have stopped running sooner but nature will tell you if things aren't healing well. I don't think I'll try to pick up running again but skipping rope for short periods to time doesn't seem to bad on the knee. (So far at least but I do need to be careful)