I have had it on good authority from a friend who is a loving mother,
that the most natural, comfortable and easy position was the one in
which she chose to give birth. She was leaning forward, leaning on the
head of the bed, and the baby came out behind her.

Gravity definitely helped - I don't know if it opened the pelvis or
not, but she and several others I have been swearing by this way of
giving birth.

The very sight of stirrups anyway is enough to make me cringe and I
certainly wouldn't see it as a comforting or welcoming sight when I'm
in full labor.