The result: The trial showed that in the working phase, sitting in a reclining position, regardless as to whether the back was concave or convex, the height increases and then reduces again when standing. This is explained by the differing pressure on the intervertebral discs, brought about by the body weight and the work of the muscles in holding the body upright. When seated in a reclining position the muscles are relaxed. Part of the body weight is taken by the backrest. The pressure on the intervertebral discs is reduced.
The conclusion therefore: The previous view is proven wrong!
• Seated activity, whether with the back concave or convex, leads to an increase in height. The load or pressure on the spinal column is less than when standing,
so sitting reduces the load!
• The view, disseminated in the literature and in countless training programmes, that a hollow back shape of the lumbar vertebrae column is preferable to a convex back shape when sitting, as the loading is less, is proved wrong in this study.
Sitting with a convex back also takes off the load!
