I am a 27 year old male. About 6 weeks ago I began having pain in my right knee. I can t remember any specific injury that would cause it nor was I particularly active when it started. When sitting still or just walking there is just a mild ache or feeling of discomfort, but nothing bad. When I go to run fast there is significant pain after the foot is taken off the ground for the next step. This pain is generally in the gap below the knee cap. There is also pain when there is any backward force placed on the straightened knee. However the thing that causes the most pain is when I cross the affected leg over the knee of the unaffected leg when sitting. This causes significant pain on the lateral aspect of my knee though rarely it is felt on the medial side as well. I went to see my Family Doctor about this last week and he didn t come to anything conclusive other than to say that it could be a meniscus issue. In his exam he only noted slight swelling in the knee, pain when backward pressure was placed on the knee, and a small bump on the lower lateral side of the knee cap when the knee was fully straightened and quadriceps flexed as opposed to the other knee (which he thought might be bursa inflammation). His recommendation was just to wait and see, however the problem is kinda annoying and I m just wondering if anyone else might have an idea as to what is causing this.