A question for the women out there

I’ve been reading “The Woman’s Book of Yoga and Health” by Linda Sparrowe and Patricia Walden. In the book there is a sequence for healthy menstruation on page 100. All of the poses are suported with bolsters or blankets.
The order is

  1. reclining bound angle pose
  2. Child’s pose
  3. Head-on-knee pose
  4. Three limb intense stretch
  5. seated forward bend
  6. wide angle seated pose 1
  7. wide angle seated pose with a twist
  8. Wide-angle seated pose 2
  9. Inverted staff pose
  10. Bridge Pose
  11. Corpse pose.
    In the book inverted staff pose uses a folding chair and is supported with bolsters. I live in Japan and don’t have access to a folding chair. Is there other options for supporting that pose? Should i do something else?
    I have the same question about chair-supported versions of half-plough pose and half shoulder stand.