Intervertebral discs seperate the vertebrae from each other. On one hand, they have influence on the mobility of the spine, on the other hand, they act as shock absorbers for the loads impacting it. The vertebral discs consist of an external fiber ring and a gel-like inner core. The water content of the inner-core is very important for the separation of the vertebrae and buffer function. The external fibre ring makes it possible that the discs may expand or contract. The painless and unimpaired mobility of the spine depends on the unimpaired function of the discs.