sfh legs, i've had exactly the same problems as you since about February. In fact, it started the very same day that my shoulder injury stopped hurting! So my running this year has not been going well. I got to the stage where it hurt every time my foot hit the ground, then it started really aching after, particularly going up the stairs (very painful!) or lying on my side. I've had blood tests, xrays and ultrasound scan, all of which showed nothing wrong. I was having physio earlier in the year, but i'm not working at the moment so that got too expensive to continue. I've had quite a few rest periods and it is now not nearly as bad as it was, but still a slight niggle to tell me it's not gone away completely. I've just started to up my mileage again and am waiting to see what happens!! I believe it is solely down to very tight muscles around the hip and lower back area and that the tensor fascia lata is getting overworked due to a weaker glutes. I have a MRI scan coming up on Wednesday, so hoping that won't show up anything too bad!!