What about that mid back where are lower ribs are dropping towards the hip bones? Such an easy place to hold tightness and to compress our digestive organs. Of course, your supported back bend and psoas opening techniques touch the area, but if you are ready to get in more deeply, you will need to do some self-massage. Being supported by a bolster helps this work immensely. Try this practice several ways: put a ball on either side of the spine or both on one side. Make sure to move your body from side to side to receive the massage sensation and to move the self-massager to different places on your back to find the most interesting and sensitive spots. Notice the difference between left and right. Practice this daily for the best results!