Any exercise is better than none, so I sometimes lie on the bed and do hips and pelvic exercises also I have cold packs from our local chiropractor at Barton, Torquay they are great but was told never to use hot pads on inflamed muscles. I've also found that when joints inflamed I gently walk and exercise making them numb and pain decreases to an acceptable level remembering you can't give in to it, good luck.

Same here! Yin Yoga has helped me. Going on low carb diet helped also. Cosentyx helps. Still have terrible SI Pain yes, radiating from tailbone to hips/Sits bones. On ice now :(. Sitting makes it worse so I bring something soft to sit on or put behind my back....or both. Cannot plan long trips. Already have Cervical and Lumbar fusions. Just herniated disc above my Lumbar surgery, praying I don't have to add to the mix! Have many auto-immune issues so that adds to the situation.

My tailbone, lower back and right hip are my worse areas. It all started in my right hip and has moved to the tailbone and lower back. Stretching does help. I know it hurts a lot but the looser you can keep the areas that bother you, the better it will be. If I stay still for periods of time I hurt worse. If I move around, stretch and do some exercising, it does help some what.

standing and god forbid sitting for more than 15 mins I'm in so much pain and really in need of a lot of ice packs

Try the piriformis stretch. It's also helpful for the lumbar spine and hips. And that loose but painful feeling in the lowback/pelvis. It works right away like magic. Look for it on YouTube.