Yesterday I woke in the night feeling like I had twisted my left leg. When I got up, the hip and knee were painful when I put weight on it. I was due to meet some friends for a walk but found I was getting pain that shot along my hip to knee and then down to ankle with every step. I had to turn back and usually I walk a lot but the last month I haven't been doing so much as no longer need to do school run. Any ideas what it can be? Booked in to go but not until next thurs.