Is Gymnastics Exposure Associated with Skeletal Benefits in the Forearm in Young Children?

The amount of bone gained during childhood and adolescence impacts greatly on lifetime skeletal health and it is well accepted that physical activity during growth increases bone acquisition. Gymnastics training results in unique high mechanical loading to the skeleton and therefore, provides an excellent model for assessing the effects of weight-bearing physical activity on bone development (Daly et al., 1999). Young recreational gymnasts experience loads up to 3–10 times that of body weight on their feet and hands. Previous studies in young adolescent competitive female gymnasts have shown that they have 8–23% areal bone mineral density (aBMD, cm/g²), at the total body, lumbar spine and hip (Laing et al., 2002; Faulkner et al., 2003; Erlandson et al., 2011a). It is often presumed that higher the aBMD or BMC translates to greater bone strength but when estimating whole bone strength (resistance to fracture) it is important to assess bone size and geometry in addition to parameters charactering bone mass and areal density (Kontulainen et al., 2007). Therefore, it is important to assess the geometrical indices of bone and not simply aBMD or BMC. Peripheral quantitative computed tomography (pQCT) is a novel technology that is able to measure bone cross sectional properties in three dimensions. It has been recently observed that early recreational and precompetitive gymnastic participation may confer 6–25% greater adjusted bone strength, as assessed by pQCT, at the distal radius compared to individuals not involved in gymnastic training (Erlandson et al., 2011b). What remain unsubstantiated are the long term effects of early recreational gymnastics on the development of childhood bone strength. Therefore, the primary purpose of this study was to investigate whether gymnastics exposure was associated with estimated bone strength development derived from pQCT at the distal radius in young males and females.