Good luck Selkie, I've also had hip flexors/hamstring/quad/etc issues as well. Glad you are working with a PT to help resolve your issues. Interestingly enough I am having more positive results in that area with the group training I currently do at my gym - and that includes two long bouts of physical therapy. As intense as the workouts are, he won't allow us to do anything without proper form. Considering how intense things are this is a good thing...

I've posture issues as well, just too many hours/days/years hunched over a computer. Working on this...