I've had PFPS for a while now and am trying to get back to easy running. I tried running but with a slight crouch, a bit like an athletic stance with bent knees and hips. Another way of thinking about it is that I just dropped my hips about an inch or two. It felt it helped me land with lower impact, and the impact that I did feel was absorbed by my leg muscles rather than my knees. The downside is that it definitely worked my quads and calves a bit harder. I had to take a few walking breaks and my quads and calves have a touch of soreness today.
Is that a good approach? What have others tried? For example, Chi running says to run taller and that seems like the opposite of what I'm doing. OTOH, Chi running also says to land with a bent leg and that is one thing that I'm doing.