Influence of mechanical signaling on bone development in children and adolescents

Abstract

Purpose of review: To study the relationship of muscle force and mass with bone mass and geometry in the developing skeleton of children and adolescents. Recent results over the last 10 years are discussed and Harold Frost's ‘mechanostat hypothesis’ is examined. Recent findings: Bone mass and geometry are related to the development of body size and muscle force in children and adolescents. Bone is therefore adapted to the tissue strain due to biomechanical forces. This process is modified by hormonal signals (estrogens and androgens). The quantifiable relationship between muscle force and bone stability can therefore be used to distinguish between primary and secondary bone diseases. Primary bone diseases are characterized by a disturbed adaptation of bone to biomechanical forces. In contrast, secondary bone diseases show a correct adaptation of bone to reduced load caused by a decline in muscle force. Summary: Our findings induced us to introduce the ‘functional muscle–bone unit’ into the diagnostics of pediatric bone diseases. The ratio of two parameters – bone strength and biomechanical forces – can be used to distinguish between primary and secondary bone diseases.