Constant muscle cramping/locking up...mainly the calves and fingers...and this is the worst...ok, lets say youre standing or walking, all of a sudden you hear an internal cracking noise from your knee and fall to the ground. You know you didnt break or sprain your knee because its not excrutiating pain, but its painful enough to maybe make you want to cry. It eventually goes away but there is a throbbing sensation for a few days. Well its happened to me twice now, just falling to the ground and hearing like a crack in my it the meds or lupus?