Chapter category: Endocrine
What Is Osteoporosis?
Growing Bone
Second Edition
Edited by: James F. WhitfieldISBN: 978-1-58706-156-1
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Chapter authors:
James F. Whitfield
Osteoporotic postmenopausal women don’t need to fall or hit something to break their fragile bones. Their, hips, ribs, wrists and especially vertebrae are apt to be broken or crushed by bending spines, muscle pullings and the low-impact bumps of ordinary daily activities. In fact the greatest bone breakers are the person’s muscles because as R.B. Martin et al. (1998) pointed out “....the muscle forces acting on the skeleton are quite large relative to the forces exerted on it by the outside world ”. Those women who were lucky enough to have put enough into their bones when young to keep them above the “spontaneous” fracture threshold during the postmenopausal years of accelerated bone loss may only become “osteopenic” or pseudo-osteoporotic. Their osteopenic bones are more likely to be broken by falls and other bumps and blows due to poor eyesight and balance (Boxsein, 1999). But these bones are still strong enough to resist being broken by the weakening muscles of older people during their declining activities. However, weakening muscles are not unmixed blessings for bones because there has to be enough muscle loading and strain to placate the bones’ thrift-minded mechanostatic mechanism which is programmed to destroy understrained bone rather than waste hard-earned resources to maintain it (Noble and Reeve, 2000; Skerry, 1999).
James F. Whitfield
Institute for Biological Sciences
National Research Council of Canada
Ottawa, Ontario, Canada
Additional chapters from this book:
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While the PTHs are by far the leading anabolic agents for treating osteoporosis and mending fractures, another family of drugs has been trying to challenge them but with very mixed results (Mundy, 200...
OGP—The Osteogenic Growth Peptide
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Scooping out the marrow or driving a nail into the marrow cavity of a bone such as the tibia, like a fracture, causes the marrow cavity to fill with a blood clot and releases a shower of osteogenic si...
The Clinical Prospects of the Invincible PTHs
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The osteoporosis market is a rapidly growing “marketer’s” dream. And several years ago there was no known bone-growing drug—only the ever-worrisome (for cancerophobics) estrogens and the other...
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Menopause and Bone Loss
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So far it has seemed that estrogen is the primus inter pares of an ever-growing number of agents that control bone growth and strength in both women and, perhaps surprisingly, men (Baylink et al, 1999...
BMUS—The Microcrack Fixers
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At first sight bones are inert, rock-like things that store 99% of the body’s calcium and consist of a hard shell, the cortex, that encloses a deceptively delicate lattice of struts and plates (Jee,...
What Is Osteoporosis?
James F. Whitfield
Osteoporotic postmenopausal women don’t need to fall or hit something to break their fragile bones. Their, hips, ribs, wrists and especially vertebrae are apt to be broken or crushed by bending spin...
