Background: Bone densitometric data are often difficult to interpret in children and adolescents because of large inter- and intraindividual variations in bone size. We propose a functional approach to bone densitometry that addresses two questions: is bone strength normally adapted to the largest physiological loads represented by muscle force, and is muscle force adequate for body size? Methods and Results: The theoretical background for this approach is provided by the mechanostat theory, which proposes that bones adapt their strength to keep the strain caused by physiological loads close to a set point. Because the largest physiological loads are caused by muscle contractions, there should be a close relationship between bone strength and muscle force or size. The proposed two-step diagnostic algorithm requires a measure of muscle force or size and a measure of bone mineral content at a corresponding location. Conclusion: This approach justifies the hope that more detailed insights into this matter could help devise targeted strategies for the prevention and treatment of pediatric bone diseases.

Keywords:
Osteoporosis, Functional muscle-bone unit, Bone density, Densitometry, Muscle force
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2007
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