The effect of mechanical loading on the size and shape of bone in pre-, peri-, and postpubertal girls: A study in tennis players

Abstract

Exercise during growth results in biologically important increases in bone mineral content (BMC). The aim of this study was to determine whether the effects of loading were site specific and depended on the maturational stage of the region. BMC and humeral dimensions were determined using DXA and magnetic resonance imaging (MRI) of the loaded and nonloaded arms in 47 competitive female tennis players aged 8-17 years. Periosteal (external) cross-sectional area (CSA), cortical area, medullary area, and the polar second moments of area (Ip, mm4) were calculated at the mid and distal sites in the loaded and nonloaded arms. BMC and Ip of the humerus were 11-14% greater in the loaded arm than in t..