I can run and have no pain, but the instant I stop and walk, one knee feels like its going to collapse and is very sore when extended on the back stride.
The pain is bad and I can walk on tip toe and finish the stride at mid body...
After rest and the next day its fine again, but repeats if I run.
Answer by Dominique:
Thanks for your question about your knee pain. First of all, apologies for not answering this query sooner, it got lost somehow in my system and then suddenly 'popped up' again.
This sounds like it could be an overuse injury. With many issues like these you can find yourself feeling fine when you run, but then when you stop the affected area suddenly hurts.
A real problem can be that people just continue with what they do, with the possibility of making this worse and worse, until it becomes a chronic injury.
As with any overuse injury, it is best to rest for a few days and ice the affected area. Icing will help to bring any inflammation down.
If problems persist (pain, swelling, etc.) do not hesitate to go to your physician or a specialist like an osteopath or physiotherapist.
If you find that this is a problem that comes and goes continuously, then try to work out what is causing this. It could be higher speed work (you will pound the pavement more when you run at high speed) or hills (very tough on the knees) or maybe increased mileage.
It may also be worthwhile to pay a visit to a specialized running shoe store to get an opinion about your foot type and your running shoes. Many knee problems are caused by insufficient cushioning, which makes your knees move around more than they have to with every step you take.
That's about as far as I can go with the "general advice". If problems persist, please go to an osteo or physio, they can be real life savers when it comes to the knees.
Hope this helps a little.