Effects of seated lumbar extension postures on spinal height and lumbar range of motion during prolonged sitting

Practitioner Summary: Unsupported sustained lumbar extension and supported dynamic lumbar extension postures may serve as effective and practical methods for reducing rate of SH loss and maintaining LROM. However, these postures should be further examined in various 'doses' to define optimal protocol for effectively minimising SH loss over time. Prolonged sitting during sedentary work has been reported as a potential risk factor for low back pain. Furthermore, prolonged sitting can result in both reduced spinal height (SH) and lumbar range of motion (LROM). This study compared the effects of no intervention (control) with two recovery postures on SH and LROM (flexion and extension) during prolonged sitting. Twenty-four participants were randomly assigned to three interventions for three consecutive days. The interventions comprised two seated lumbar extension recovery postures (unsupported sustained and supported dynamic lumbar extension postures) and a control. Both interventions facilitated a relatively short recovery period for both SH and LROM. Supported dynamic lumbar extension conditions significantly helped SH recovery, as compared with control condition, after the first recovery posture intervention, and both postures have potential to maintain LROM. However, both postures failed to induce SH recovery over an extended time.