SITTING TAKES THE LOAD OFF THE INTERVERTEBRAL DISC
- Research conducted by
- Prof. P.Brinckmann, Independent Lecturer Dr.Drerup, K.Ehrenbrusthoff, Institute for experimental biomechanics at the University of Munster
- The aim
- To find the extent to which sitting and standing loaded (puts pressure on) the intervertebral disc.
- The trial
- A stadiometer (a device for precise measurement of height) provides information about the loading on the spinal column under simulated office activity. The test was split into three phases (each of 30 minutes), in which the subjects stood in the initial phase, sat in the working phase and stood up again in the follow-up phase. Between the individual phases the height was measured ten times. Taking off the load led to an increase in height, applying a load led to a reduction.
- 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!
