Anyone used something called the Pink Kit? See www.commonknowledgetrust.com
With DS1 I got stuck on my back by mw, because baby needed "constant monitoring". I only realised afterwards that she did not do any monitoring! Pushing was very difficult on my back, but doctor who came in after I had been pushing for AGES suggested a very small change in the angle of my hips, and baby slid out easily!
For no2 due Sept, I decided to get all the info I could about birthing and positions etc. I wanted to know why such a small hip movement had made all the difference. And I wanted to be the one to decide on the best birthing position.
I found this Pink Kit, which is brilliant (am busy working through it myself at the mo). It is a collection of wisdom from thousands of women and their birth partners, on things that did or did not work for them in birthing. It is a book, video (or dvd) and audio tape (or cd). It talks of different birth positions and different techniques to try if your baby seems "stuck". It recognises that there are different shapes of pelvic openings, and some positions actually lessen the space available for baby to come through (depending on the woman's shape, and the baby's position). (Eg, squatting is great for certain pelvic shapes, but closes up the birth canal for others).
Basically it shows you some techniques you can try before you get into labour to test to see what positions give the most "space" for your particular pelvic shape. It also gives some exercises and advice about relaxing through contractions (and practical ways of doing it!). It recognises that every woman is different, as is every baby, but gives info on what has helped other women for generations.
In the book I found the hip movement that the doctor had suggested while I was in labour with DS1. If I had known this myself, I would have been able to do it sooner in the process before I was utterly exhausted.
I have heard of many people who struggled in earlier births (and some who were told their pelvis was too small for vaginal birth), who were able to give birth fairly easily after using this kit. It obviously does not guarantee anything, but contains valuable info that gives you a much better chance of avoiding intervention, feeling more in control and minimising pushing time. It also provides info on massage techniques for the perinium to help minimise chances of tearing or episiotomy (have not tried it yet, but figure anything is worth a try if it helps). Already the things I have learned have made me much more confident.
Good luck