Knee hurting? If so, join the multitude of runners that suffer from knee issues. I'd suspect knee pain is the number one injury that runners must suffer through....if, in fact, they can work their way through. Many times we runners focus on trying to solve the pain, rather than trying to fix the problem that's causing the pain.
Certainly there are times when the knee pain comes directly from an issue within the knee itself, but not always. Sometimes the pain you can put your finger on down on your knee isn't caused by an issue within your knee, but rather by issues with other joints, such as weakness in your hips.
Maybe that's your problem. If so, often simply strengthening your HIP helps solve the knee problem. The various exercises you see below can help this. These are very basic and simple strengthening exercises that you can do lying on your den floor.
In one of my visits to a medical professional a few years ago, I was given this basic knee/hip exercise sheet. (Hope it's not copyrighted!).
First, let me quickly say that I'm not a medical professional and I have absolutely no knowledge of the inter workings of the knee or the hip. The only knowledge I have comes from 40 years of dealing with my own....and my student's knee issues. I do know these are very elementary exercises that will be good for you and your running, regardless of whether they solve your knee problem or not.
As with most things, start low and build. Think about maybe 4 times a week for 3 weeks before you begin to see some improvement. Maybe start with a repetition of 5 each, and progress to 15 or 20, per exercise. You can add ankle weights if you desire.
Hope you are one that can achieve positive results from this strength training.