[Contribution toward determining the inner equilibrium of the spinal column (pivotal point as temporary pole) (author's transl)].

The estimation of the centre of rotation of a spine segment can be shown as a transient pole, which follows the polar curve of the movement of the upper segment of the spine, relative to the lower one. With the help of X-ray, it is possible to evaluate two separate positions of the pole, from the normal position to the medium flexion and from the medium to the extreme flexion of the lumbal segment. Based on these expected values, as well as their intervals, pathological cases can be recognized, which is also shown in an example.