Postural problems when sitting
Changing from standing to a sitting position forces the top of the pelvis to rotate backwards. This flattens the natural lumbar curve in the spine, causing increased, uneven pressure on the intervertebral discs. On leaning forwards (80° angle) to work the spine becomes ‘C’ shaped, further increasing lumbar disc pressure (+190%) and placing extra strain on the supporting back muscles. Movement is restricted with breathing, digestion and circulation adversely affected.
How posture controls disc pressure
The secret of sitting to reduce disc pressure is to encourage the spine to lengthen into its neutral ‘balanced’ position, as in standing. By sitting upright and leaning slightly backwards (100° angle) the top of the pelvis rotates forwards allowing the spine to return to it’s natural ‘S’ shape. There is better balance within the body, with the head centrally positioned over the spinal column. Weight is more evenly distributed across the intervertebral discs and less activity is required from the supporting musculature.