If the hip twisting is too much of a stress, it stresses the multiple tendons and strong ligaments holding the hips to the sacrum, exactly like excess pressure on a building’s supporting girder. The ligaments and tendons holding the spine next to the hips get stretched and irritated. For most of Us, this is not a problem.
We can detect our right or left shoulder being a little higher than the other easily by observing ourselves in the mirror.
We can learn to feel that one hip is higher than the other by putting our hands on the top side of the hips on the right and left sides.
It does take a little experience to learn how to do this. I watch people on the street as I walk behind them to observe which shoulder is higher.
When this causes the sacroiliac pain:
For some of us, this slight bit of excess forward rotation produces increased stress on hip tendons and ligaments.
Pain starts when one day the stress is too much: then hip pain starts.
Stressed tendons and ligaments are the causes of almost all low back/hip pain, and rarely from a lumbar (lower spine level) herniated disc.
A degenerated disc is another topic, which we will reserve for it’s discussion.