I have left knee pain, more behind the knee, also lower left back pain. That seems to be more annoying than painful and I keep getting a sharp stabbing pain in my inner thigh it feels like the size of a quarter so weird, if I sit to long have a real hard time walking, can beat weight on it as long as I keep knee on stiff side, if I turn without moving foot pain is excrutiating, today when I walked off a step it felt like pain exploded behind and on the sides of my knee almost brought me down, I know of no injury that I did but this is affecting my everyday routine and my walking gait which affects my back also