Over the past several decades ‘good’ and ‘bad’ posture has been to a large degree based on experimental data concerning the hydrostatic pressure of the nucleus. These studies found that lordotic postures reduce the pressure in the nucleus compared to flexed postures and they concluded that lordotic postures reduced spinal loading. We now know that lordotic postures reduce nucleus pressure only because they transfer load-bearing to the posterior annulus and zygapophysial joints. These structures are frequently sources of back pain themselves, whereas the nucleus is not…so the concept of ‘good’ posture needs to be re-evaluated.
There are advantages to BOTH lordotic and moderately flexed postures dependent on numerous variables including whether one is moving, static standing or sitting or lifting. Recommendations should also incorporate the need for consistent postural ‘adjustments’. Additionally internal disc disruption (IDD) degenerative changes and pain alter load-transfer and increase ‘peak-stress-concentrations’ on the disc further complicating the concept of ideal posture.