@denisejones00 - I believe my pain is caused by the SI joint, but after diagnostic tests and one steroid injection, I was skeptical. My pain is a dull ache in my right buttock that can stop me from walking around the block (and I'm an athlete; tennis, fly fishing, basketball).
I started doing a regimen of PT daily for the last 13 days and I'm feeling a lot of relief! My docs in my area, so far, have offered to explore my lower lumbar with an MRI after I complained that the SI joint injection was of no help. But I'm going to continue to strengthen and stretch with PT until it doesn't help me! I would say I am 70% better due to PT.
Thanks for your encouragement with the PT!