Knee pain you say?
With the traditional marathon season now behind us but more and more people wanting to run trails, ultras and marathons throughout the calendar year, I've seen a lot of people of late with knee pain.
Whilst it's quite natural to assume that the best way to combat this is to strengthen and stretch the quad group as it is the most connected muscle group with regard to the knee, I have found in my work that strengthening the hip abductor group gets better results. If you improve your hip stability I feel sure you will see better movement patterns and this ultimately takes away any issue of excessive force that you may previously be putting through your knee joints.
As with everything though, get it checked out, don't guess.