A year or so ago, I began having some pain in my left knee, that I believe to be from overuse. It will occasionally become painful, and usually just be a dull throbbing I can ignore. A couple of days ago I was hit by a car at VERY low speed. I was facing the car and the impact hit my left leg right below the knee. Since then, the pain has been almost continuous, getting into excruciating pain if I leave my leg in one position for any length of time and then try to move it. Does anyone have any idea what a medical diagnosis might be, or what to do about it? The pain is mostly right above the kneecap in the front of my left knee, and there does not appear to be any bruising or swelling, just a lot of pain.