I can’t let this get by..yes I do have something going in my knees. they make a crackling sound sometime and get hurt a little no matter what position I put them in. But get this, those are the only joints in my body that is not double jointed or very flexible! Go figure on that one. I can’t even pop my knuckels or my toes cause they just slip out instead of making the popping sound, and that hurts!