Spine twist at exercise 18 really is a release. It helps unwind the spine from the inverted series and the front body opening series. The position is often the hardest part of the spine twist. Seat on something to help you lift out of your hips. Then play with your rotation. Lead with your breastbone. Take big breaths to help open the ribcage.
Primary focus: Thoracic Mobility
Secondary focus: Space in the lumbopelvic region