<human>: My name is Matt and I'm 16 years old.

A few months ago I developed a lower back pain out of the 'blue' and I do not know what caused it. It is on my very lower back area, on the left side. Every time I move at all, it feels like someone is driving a knife into my back and it is an extremely sharp pain. I can move my right leg freely without pain, but my left leg, every time I move it or put pressure on it (i.e, standing on it, walking on it, etc.) It has that sharp pain.

I've been to the doctor's office a couple of times, he keeps telling me to go for X-Rays and I have been, so far nothing has come up and he just continues to tell me to get X-Rays and take TYLENOL, which don't work the slightest bit. The doctor around here is no help.

Basically,

Summarize the given text in a few sentences.
<bot>: Extremely painful lower back pain on the left side, feels like a knife is being driven into my lower back whenever I move my left leg or put pressure on it.