Tailbone Coccyx center cut out cushion.

[AngleOff66]

Saw these and thought that it may work for someone.   There are plenty of other styles as well. 

https://www.amazon.ca/Everlasting-Comfort-Orthopedic-Sciatica-Tailbone/dp/B01EBDV9BU/ref=bmx_dp_kgexgzqn_1/134-9559785-5451040?pd_rd_w=DH1zy&pf_rd_p=aa5a6837-dc2f-41da-8ea4-563c5d415b8d&pf_rd_r=ZT2264GRDRZJJXD6M8V4&pd_rd_r=5e7fc2ea-ef53-441d-b7b9-2f1d1717e354&pd_rd_wg=LREdf&pd_rd_i=B01EBDV9BU&psc=1

1) You might have to flip it so that bulge isnt in behind.

2) Not sure that the gap in the middle is large enough for full range of motion of the stick?