I was working with this yesterday and found it extremely useful. Give it a try and let me know what you think!
Two straps. One around each thigh, threaded toward the midline creating internal rotation. Bring length of straps between your legs and wrap around outer thighs with crisscross between inner thighs. Pull straps in front of you to create internal rotation in the thighs and pull the heads of the arm bones back.
Next wrap the length of the strap around your upper trapezius muscles threading from the front. The length of the straps will crisscross at the back. Pull down to create internally rotating thighs as you backbend. Pull through to front under armpits, threading under shoulder blades. Maintain crisscross at mid-back. Pull up as you go back. Super supportive!
You can also pull the straps forward and pin them under your hands in downward facing dog. I also put them under my elbows in sphinx pose. Both excellent support.