[A new theory of the etiology of osteoporosis (author's transl)].

A new theory of the etiology of osteoporosis--inaugurated by the author and developed in cooperation with Fricke--is step by step elaborated and explained. Alteration of the bone marrow is observed simultaneonly with osteoporosis--caused by reduced blood flow in bone and bone marrow, and promoted by reduced muscle work, i.c. inactivity, influencing blood circulation in bone and bone marrow. Alteration of statics and vertebral bodies resulting from bone atrophy and reduced muscular force are newly interpreted by a new theory capabilities of radiological osteoporosis-diagnostis are preceding.