Changes of positions during labor, including lying on one's back can truly save a baby's life if his/her heart rate slows too much due to the pressure of birth at the very end of labor.
It's nice to know what to do to get the baby born quickly. I had to learn how to act quickly to save lives. Birth is mostly normal most of the time, but when it deviates from normal, it's nice to know what you're doing. Why not arm yourselves with knowledge that can keep a mother and baby alive and well- even if you never have to apply that knowledge to your practices?
I honor the granny midwives of old. It's hands on experience and observation that ALL good midwives have truly learned the most from. And, faith in God!
An anterior lip of cervix can stop a baby from being born, but it's so easy to get it to slip over the baby's head if the laboring mom just lies down on the floor (hard surface) and pulls both her knees back and up with her hands, then bears down firmly as her midwife pushes the lip back with a gloved hand. All is takes is one finger to coax the cervix, which usually will slip right over the baby's head, allowing the baby to drop down and get born quickly!
There's no need to make mom suffer for hours longer when the midwife can so easily help her and her baby. The baby gets tired too.
The reason for getting mom on her back is simple. The anterior lip of cervix is caught between the mother's pubic bone and the baby's head. When mom lies down on a firm surface (not a bed), the baby drops down into her back allowing a space to open where the cervix was trapped before. When the midwife, with a gloved hand, then nudges the cervix, AS THE MOTHER PUSHES, it slips so very easily back, allowing the baby to immediately drop down and begin its journey to the outside world.
When the mom simultaneously pulls her knees up and out and back, she opens her pelvis as wide as it can go, and voila- baby comes quickly!
Midwives do not take away a woman's power by helping her. It show compassion and skill to have this kind of knowledge to help mothers in labor. That's what midwife means- "with woman!"