Rachael, I visited a physio for very similar sounding knee problem and was given a few simple exercises to try.

Sit on the floor or an extended seat and flex your thighs holding for a few seconds, this can also be done in the morning before evening getting out of bed.

When watching tv sit on the floor against a seat or the wall, roll up a towel and place under your knee elevating it.  Flex to lift your foot off the floor.  You can also turn your foot out to the right or left.

This worked for me, I went from pain after only 4 - 5 miles and can now run a half marathon/kilomathon pain free.

Nick - I have n't read the book but I can confirm the benefits..

On Christmas morning I went for a run in the lanes where I live and wore running spikes in the snow and ice - magical. I ran 10km in less than 50 mins and felt great at the end, no soreness or aches at all.

Roll forward a few months and I had the opportunity to run 35 mins barefoot on a beach - again magical. When I stopped and checked my footprint (Robinson Crusoe moment), it was easy to see what my feet were doing. In my case, landing cleanly with no heel strike , no burying of the toes with an exaggerated push off etc etc. All of this meant no stress on my lower limbs.....

If we could run like kids and abandon the "bricks" we all buy I think we would all be better for it ....a pure form of running is indeed magical.

For the avoidance of doubt choose your site carefully - I wouldn't run barefoot through many UK parks unless I knew it was safe underfoot....

But - if you can find a place to have a go you will really feel exhilerated.   

Hi Rachel,
A few years ago I injured my knee in the Gym. I was in some serious pain for a considerable amount of time (weeks and weeks) before I finally conceded that I should seek some kind of professional assessment. So I made a routine appointment with my GP. He then asked all the obvious questions about how and when etc etc and duly sent me for x-ray. The xray showed nothing but my doc did say something which for some strange reason, has stuck in my mind ever since. 
"The knee is a very complex joint, probably the most complex in the whole body. It's made up of bone, muscle, ligaments, cartiledge & tendons all combining together to work the joint. So any injury to the knee can be down to stress or damage to any one or any combination of these parts. We need to understand the mechanics of the knee to keep it injury free while doing exercise.
The key is to exercise all of the parts of the knee joint by doing different movements and motions."

If you search around t'internet you'll find loads of useful tips and advice for knee execises and how the knee works.

Try this one for starters, it may help,,, http://www.arthroscopy.com/sp05001.htm
Good luck

Hi Rachel

I would also definately recommend getting a proper gait analysis done to make sure you have the correct running shoes for you gait. Then if you havent already...invest in some decent correct running shoes.