Just a quick update: I did that stretch before riding in my lesson this afternoon, Flamingorider, and it helped A LOT. My hip flexors are yelling at me right now, but it was worth it; I was able to open up my hips and let my leg drop naturally and as a result, my upper body position improved dramatically!

Now to just get a massage therapist, so my decrepit old body won't react QUITE so badly a few hours after an hour-long ride...