College of Kinesiology, University of Saskatchewan, Saskatoon, SK, Canada; Lithuanian Sports University, Kaunas, Lithuania.
J Bone Miner Res. 2013 Dec;28(12):2592-600. doi: 10.1002/jbmr.1986.
Gymnastics, a high-impact weight-bearing physical activity, has been shown to be highly osteogenic. Previously in this cohort, bone mass development (bone mineral content accrual [BMC]) was shown to be positively associated with low-level (recreational) gymnastics exposure (1 to 2 hours per week); however, BMC is only one single component of bone strength. Bone strength is influenced not only by bone mineralization but also bone geometry, bone architecture, and the imposing loads on the bone. The aim of this study was to investigate whether low-level gymnastics training influenced the estimated structural geometry development at the proximal femur. A total of 165 children (92 gymnasts and 73 non-gymnasts) between the ages of 4 and 6 years were recruited into this study and assessed annually for 4 years. During the 4 years, 64 gymnasts withdrew from the sport and were reclassified as ex-gymnasts. A dual-energy X-ray absorptiometry (DXA) image of each child's hip was obtained. Values of cross-sectional area (CSA), section modulus (Z), and cortical thickness (CT) at the narrow neck (NN), intertrochanter (IT), and shaft (S) were estimated using the hip structural analysis (HSA) program. Multilevel random-effects models were constructed and used to develop bone structural strength development trajectories (estimate ± SEE). Once the confounders of body size and lifestyle were controlled, it was found that gymnasts had 6% greater NN CSA than non-gymnasts controls (0.09 ± 0.03 cm(2) , p < 0.05), 7% greater NN Z (0.04 ± 0.01 cm(3) , p < 0.05), 5% greater IT CSA (0.11 ± 0.04 cm(3) , p < 0.05), 6% greater IT Z (0.07 ± 0.03 cm(3) , p < 0.05), and 3% greater S CSA (0.06 ± 0.03 cm(3) , p < 0.05). These results suggest that early exposure to low-level gymnastics participation confers benefits related to geometric and bone architecture properties during childhood and, if maintained, may improve bone health in adolescence and adulthood.
体操是一种高强度的承重体育活动，已被证明具有很强的成骨作用。在此前的队列研究中，骨量发育（骨矿物质含量积累[BMC]）与低水平（娱乐性）体操接触呈正相关（每周 1 到 2 小时）；然而，BMC 只是骨强度的一个单一组成部分。骨强度不仅受骨矿化的影响，还受骨几何形状、骨结构和骨骼承受的负荷的影响。本研究旨在探讨低水平体操训练是否影响股骨近端的结构性几何发育。本研究共招募了 165 名 4 至 6 岁的儿童（92 名体操运动员和 73 名非体操运动员），并在 4 年内每年进行评估。在 4 年期间，64 名体操运动员退出了这项运动，并被重新分类为前体操运动员。对每个孩子的臀部进行了双能 X 射线吸收法（DXA）成像。使用髋关节结构分析（HSA）程序估计了狭窄颈部（NN）、转子间（IT）和骨干（S）处的横截面积（CSA）、截面模量（Z）和皮质厚度（CT）的值。构建了多水平随机效应模型，并用于开发骨骼结构强度发展轨迹（估计值±SEE）。在控制了身体大小和生活方式的混杂因素后，发现体操运动员的 NN CSA 比非体操运动员对照组大 6%（0.09±0.03cm2，p<0.05），NN Z 大 7%（0.04±0.01cm3，p<0.05），IT CSA 大 5%（0.11±0.04cm3，p<0.05），IT Z 大 6%（0.07±0.03cm3，p<0.05），S CSA 大 3%（0.06±0.03cm3，p<0.05）。这些结果表明，早期接触低水平体操运动有助于儿童时期的几何和骨骼结构特性，并可能在青少年和成年期改善骨骼健康。
