I used a lot of this movement in my hospital birth too (thank goodness), fortunately I have a long background in fitness and know my body pretty well.
My favourite position is a very deep squat, like this (obv. without the bar when birthing but I train with the bar - you can use a broomstick)
https://www.davedraper.com/overhead-squat.jpg
And noooooooooo to this
https://workout911.com/wp-content/uploads/2009/07/squat_front.jpg
Try them both, you'll feel quite a difference, one engages the muscles to birth, the other just bums your knees.
If you can't even do a basic squat, start against a wall and keep up with flexibility (yoga is good), practice practice until your ass gets to the floor.