Since then, I've had a sharp pain in my left knee, just below my knee cap, but only when straightening my leg after sitting with my legs pulled in, standing for long periods, or sitting in a vehicle for long hours. Rest does not seem to help and to my knowledge, the area around my knee
is not swollen
or tender to the touch. I haven't taken any falls or landed awkwardly on it. I can run and walk on it, but it hurts after extended use. Any ideas what might be wrong?