I;m a chiropractor who learned a neat technique for handling back labor. It's hard to describe, but is written up in Midwifery Today years ago as "Posterior No More". The midwife who learned how to do it has been unsing it for 10 years and hasn't had a posterior birth in all that time.
You can also find it described in a book called "hands of love" by Carol Phillips, published by new dawn publishing.
Basically, back labor happens when the baby is descending the birth canal with Occiput (back of the head) posterior. So as they descend, the baby's nose and brow meet the pubic bone, and they pull their head back, right into the sacral nerve plexus on the front of the sacrum. That means their skull is pushing into 8, count 'em, 8 nerves, some as large as your pinky. It's not pleasant.
Things you can do - make sure your spine is in line. Get checked by a chiropractor regularly during your pregnancy. If your sacrum (triangle bone at the bottom of your spine) is misaligned, then it pulls on the broad ligament, that attaches to the front of the sacrum and the uterus, pulling your womb a bit crooked. That crookedness can effect the baby and how well they line up when the birth comes.
Get daily exercise, walking is fabulous.
Consider a cranial-sacral therapist if you have ever fallen right on your bum. That kind of fall can put tension into the fascia, which can effect the pelvic floor muscles and also the position of your womb, which then effects your baby.
Last of all, if you are having back labor, get on all fours,and have your knees up about two steps (like stairs-steps) higher then your head. Put your head down on the floor and hang out for a few minutes. Sometimes this can result in the baby actually backing up, shaking its little head, and realigning properly.
If you want more info about the technique I learned that is described in that book, feel free to pm me or email me. If I get the time, I could try to type it out here, if there is interest.
All the best
Lisa