We cannot equate this with a purely biological freedom or vitality, or spontaneity. Bergson and His Philosophy J. Alexander Gunn. It is a more serious difficulty that Paul knows of no Longobardic king with a name which we can equate with Sceaf.
But this posture makes your pelvis rock forward into an anterior pelvic tilt, which consequently creates an increased lumbar curve (lordosis). Unfortunately, other tissues such as the muscles described above adapt to this posture over time, which contributes to back pain and injury.
In the case of flat low back posture, the pelvis is tilted back, and the spine, which is brought along for the ride, is also moved back. This translates to a decrease in the amount of forward curve you have, i.e., you have less lordosis and more flattening in that area.