Depending on what is hurting/sore/whatever, have a look at Quadratus Lumborum or whatever it's called.
My physio broke me with elbows when he was investigating some back pain I had a couple of months ago...
Shall look it up
You could do the stretch where you lie on you back with your arms out like a crucifix, and alternately raise each leg across your body to the opposite hand. Is that called the crucifix?
A little bit of band distracted anterior hip stretching will help too.
Er, I lay on my back, and pull one knee over my body to the other side of the floor, that cracks it nicely and lessens the tension?
Shall look up your last quantum theory stretch as well, as I have no idea what that is.