My knee "injury" is confirmed by doctor as Osgood Schlatter Disease. "A common disease", he said. X-ray and Physiotherapy (physical therapy) can be arranged but not necessary. The pain is caused by the inflammation of my knee tendon, and the inflammation is probably caused by harsh exercise (which I don't really think so). According to the doc, I still need 2-3 months time in order to recover. That's the only bad news for my knee. *Gayness !*