Knee pain is a nuisance. I got it when training for a race but it's better now. I was prescribed:

-Patellofemoral Pain Syndrome
-12 week exercise program
-trigger point release
-joint mobilization exercise program

then ongoing exercise, attended an academic lecture on backpain and read up on psychologically informed physiotherapy for backs and 'back school' books.

Now my leg pain issues are resolved. It might be that simple for resistance training knee pain.