I have knee medial knee pain. Movement to is not restricted. If I use my fingers to try to find where it is tender I find nothing when my leg is extended when bent and I feel the centre of my knee on the inside it feels tender. I cannot be specific when the injury occurred it seemed to come on gradually. I played tennis on Tuesday. All ok. Then Friday a one hour coaching session all ok. Saturday morning a little stiff but no pain. Played 2 hours Saturday morning. Sunday morning a little stiff slight pain. Stiffness went, but if I moved quickly I got pain. I was playing a tournament. Sunday evening stiffness and pain but not severe but two sharp twinges. Today about the same and a couple of sharp twinges. I have for a few years been unable to use a stationary exercise bike because I quickly get the same pain that stops as soon as I stop pedalling. I do not get the pain riding a road bike or running. There is no swelling or heat. Any ideas?