Page "Osteoporosis" Paragraph 21

* In general, immobilization causes bone loss ( following the ' use it or lose it ' rule ).

For example, localized osteoporosis can occur after prolonged immobilization of a fractured limb in a cast.

This is also more common in active patients with a high bone turn-over ( for example, athletes ).

Other examples include bone loss during space flight or in people who are bedridden or use wheelchairs for various reasons.