Here is another supported position for breathing in the back of the body – prone savasana.
If you find it uncomfortable to lie on your front, either because it hurts your lower back, or your neck doesn’t like to be twisted to one side, then lying over a bolster, or a pillow (or both) can be very satisfying. Have your head far enough off the support that you can tuck your chin and rest your forehead on the floor or on a block.
A Space to Be 