It seems that people love to blame the discs for the pain but there are so many innervated structures in the spine that could cause pain.

Matriclar, you describe a stretch pattern of pain - that is FF and LF L produce pain on the right buttocks. This could be from ligaments, joints, disc, muscles, nerves, dura etc

More information is needed to narrow down the source and cause of the pain. Bending over and lifting with a twist can be strain at the L/S, Wikipedia reference-linkSIJ and Hip.

Fortin described SIJ pain as being from the PSIS/SIJ joint line and lower. So far, there is no L/S pain so SIJ would be ahead at the moment in the list of structures to test.

Thanks