[Strain on the intervertebral disk and vertebrae in stress].

The experimental data about the strain of intervertebral discs and vertebral bodies under physiologic loads are described; the relation between tissue strain, mechanically induced damage and clinical symptoms in the region of the lumbar spine is discussed. With reference to a paper by Kirkaldy-Willis and Farfan on "Instability of the Spine" a new representation of the interrelation between mechanical factors, pathologic changes and psychic influences in the development of low back pain is given.