When you have pain at the knee, the medical establiahment will focus in on the knee as to where the cause of the pain is. This is lunacy. I have shown in more then 99.99% of cases the cause is not where the pain is being experienced.
This holds true for knee pain amd this is a primary example of understanding the biomechanics behind the idea. If you are a runner you will want to condition yourself to prevent this from happening to you.