Mine is definitely my quad/patella tendon plus swelling plus tight band! He did three IT band tests - all of which I passed (don't ask me what he did, I was lying down staring at the wall!) and when he touched it I wasn't bothered by it, just a little tiny bit tender. I've got an inner range quad exercise - rolled up towel under knee and either press knee into the towel or raise foot up from the knee - apparently both work the same muscle. And outer range quad - sit in a chair, put a resistance band around the leg of the chair and the other end around my ankle. Starting with leg bent at 90 degrees, raise leg up from the to straight - or as near to straight as I can without it causing pain. He said that the best way to help the tendonitis is to do these exercises which will strength the quads and should help. I hope so!