My sacroiliac pain still follows almost every yoga session. I warm up with the sacroiliac mobilization series most of the time. However, I am very confused about what this series is meant to accomplish specifically? I feel the movements in the SI throughout the series but usually it feels good, like the two side of the joint are being pushed back together. Is this series intended to loosen up the joint in preparation for forward bends and twists or is it intended to correct the joint misalignment in and of itself?
It is for correcting the misalignment and freeing the hip sockets so that they have great internal and external rotation. It should be felt in the groin as well as out hip area of the tensor fascia lata. Best is to feel it there rather than the s/i during the action of the series. Modify by elevating your pelvis and let me know how it feels.
I do elevate onto a bolster or blanket already due to my knees and I feel it in the SI to varying degrees based on the day. For example lately, I can do the pelvic tilt and twist on one side but the twist hurts the other side but that is just lately. Some days it feels great, some days it feels neutral and others it is painful. One thing I have noticed lately is that in shoulderstand, my SI huts a lot. If I move my feet up toward my head the pain goes away. What do you think?
Sounds like a need to stretch latissimus along its lumbar sacral fascial band and the belly of the quadratus lumborum from your shoulderstand description. Still I would recommend elevating the bolster so you do not react at SI during the exercise itself.
All in all you describe a need for ujjaye pranayama and learning how to feel the specific motions of prana. By so doing you will begin to move beyond this limitation, for what all this describes is a pranic imbalance more so that musculo-skeletal problem. Blessings.