I had pain below my knee cap when I starting playing Beach volleyball again while I was doing 50 mile weeks. The jumping and lateral movement, expecially in the sand bothered my knee just below the cap. I stopped playing volleyball for awhile, kept running and shortened and lightend my stride a bit taking a bit more quicker steps. Pain is gone and I am running stronger as well. Actually broke my above 35 year old PR in the 10k 2 weeks ago with a 38:20. I actually counted my footfalls(Stride rate the first mile). Oh, I can jump fine now as well, I think you need to take a look at your running form.