What should I do if my knee hurts when moving from being straight to bending it. It can go completely straight and bend however it seems to catch itself when I bend it and stalls out. I feel as if there is a weight behind my knee cap. It has been like this for five days now. I am and it started hurting after my last half marathon. I have another half this coming Sunday and just want to know if there is anything I should do to help my knee recover.