You could possibly have flat feet...? That messes with the knees. I have flat feet, and I just need to get a good pair of shoes that have great arch support. A good brand is New Balance. Or you could also get good insoles to put in the shoes you already have. You could also go to your doctor. They might be able to help. One other hint is when you're running, focus on now running like an elephant. When I walk/run, I walk heavily. So you need to be able to run and not hear yourself hitting the ground. Hope this helps.
