DD was back to back with me and turned during labour. Copied the below info from the homebirth website which gives some helpful info www.homebirth.org.uk/ofp.htm
It also has stories about posterior births - they are not necessarily more difficult (these are stories of homebirths or ones where people transferred in)
If your baby is posterior when you are in labour:
Remember, most posterior babies will turn during labour (87% according to Gardberg study - see refs), but even if yours doesn't, a baby can still be born vaginally in the posterior position - "face to pubes" - and this can happen at a homebirth. Sometimes a posterior labour can make things just too tough, but it can work out.
You may try your hardest to get your baby into a good position, but he may be determined to stay the way he is - if so, there are things you can do in labour to help a posterior baby to be born.
The majority of babies who experience a posterior labour, actually start labour in an ideal position, and then turn posterior while you are in labour. Gardberg et al found that 68% of posterior babies took this route. This seems very unfair - but if it happens, these tips should still help.
These movements can help the baby wriggle through your pelvis, past the ischial spines inside it, by altering the level of your hips. They are also helpful if the baby is anterior but has a presentation problem, eg his head is tipped to one side (asynclitic).
In early labour, walk up stairs - sideways if you need to.
Rock from side to side
March or 'tread' on the spot
Step on and off a small stool
Climb in and out of a birth pool [3]
The positions listed below may also help.
For the second stage:
Use kneeling or all-fours positions. Kneeling on one knee can help.
Supported squatting in second stage, but the mother must be lifted quite high up; her bottom should be at least 45cm (18 inches) off the floor.
Birth stool seats should be at least 45cm (18 inches) from the floor.
Avoid lying on your back, semi-reclining, sitting or semi-sitting. These positions all reduce the available space for the baby to turn. Lying on the side is OK.