I haven't heard of the posterior position being more common among Asian women. A doula recommended to me that in the last month of pregnancy, I should sit on a birth ball for at least 1/2 hour 2 or 3 times a day and do pelvic tilts several times a day. Both of these things are thought to help the baby get into the proper alignment. The pelvic tilts annoy a posterior baby because it is uncomfortable for their head and encourages it to turn. Also, she recommended never slouching or laying on my back. Only sit up straight, supported by pillows. My midwife told me that these things could help but that some babies just sit in a posterior position for other reasons, like the placenta is in a certain position and the baby tends to curl around it. Anyway, I put the pelvic tilts and sitting up straght into the category of, It can't hurt so might as well try it.