This was one of the first symptoms I developed when I was acutely floxed with Cipro in March 2010. This symptom developed on Day 5-6 post. I remember it clearly, because I had never had any problems in my knees prior to this. As a vet, I was always bending down on my knees throughout the day to work with the larger dogs on the floor. Along with the developing fatigue and “feeling like I was 100 years old”, there was this rather alarming loud “snap crackle pop” that I could feel as well as hear going on throughout both knees whenever I bent them. This symptom decreased quite a bit many months after the initial acute phase. However, this also was a symptom that returned quite quickly whenever TH or Iodine increased. I rarely, if ever kneeled or crouched after being floxed, simply because I couldn’t. But I could hear this “snap crackle pop” whenever I used the stairs in my house, and this symptom waxed and waned depending on where I was at with my T3/Iodine status.