Assessing 3D Trunk Strength as a Function of Position and Velocity

描述(由申请人提供)：该申请将允许申请人攻读研究生研究学位，并通过调查运动(机械负荷)在生长过程中对终身骨骼健康的作用，为国家的健康科学研究议程做出贡献。运动是骨质疏松症的常用干预措施，因为骨骼对机械敏感，可以适应负荷。然而，骨骼对运动的反应时间(青春期前)和容易发生骨质疏松性骨折的时间(成年)之间存在差异。这就提出了一个问题：在发育过程中，运动引起的骨骼变化是否会持续到成年期，在那里它们对降低骨折风险最有利。发起人的初步数据表明，负荷引起的皮质骨结构变化会长期保持，并有助于终身增强骨强度。目前的应用将在三个翻译动物研究中进一步探索这一点，通过调查：(1)皮质和小梁部位负荷益处的短期和长期保存；(2)人工绝经(通过卵巢切除诱导)对负荷效果保存的影响；以及(3)维持或丢失负荷诱导的变化的潜在机制。在每项研究中，将分别使用尺骨或胫骨轴向载荷模型在幼鼠的右前肢或后肢诱导骨适应。左肢将作为无负荷的内部对照。随后，动物将被解除训练(仅限于笼子活动)12、18或92周，一些动物将进行卵巢切除以诱导人工绝经。骨骼对负荷和非训练的反应将使用体内和体外分析相结合的方法进行评估。为了补充这些动物研究，将进行第四项临床研究，将投掷运动员作为潜在的人体模型，探索在发育过程中锻炼对终生骨骼的好处。这是后来 这项研究将为未来这一主题的临床研究提供初步数据。公共卫生相关性：对于与衰老相关的骨质疏松性骨折风险增加，通常开出的治疗方法是锻炼。然而，骨骼在青春期左右对运动最敏感，而在成年后期容易发生骨质疏松性骨折时则不是。这就提出了一个问题：在发育过程中，运动引起的骨骼变化是否会持续到成年期，在那里它们对降低骨折风险最有利。该应用程序将调查在生长过程中锻炼对长期骨骼健康的作用。

DESCRIPTION (provided by applicant): This application will allow the applicant to pursue a graduate research degree and contribute to the Nation's health sciences research agenda by investigating the role of exercise (mechanical loading) during growth on lifelong skeletal health. Exercise is a commonly advocated intervention for osteoporosis as the skeleton is mechanosensitive and can adapt to loading. However, a disparity exists between when the skeleton is responsive to exercise (pre-puberty) and when it is prone to osteoporotic fracture (adulthood). This has raised the question of whether exercise-induced bone changes during growth persist into adulthood where they would be most advantageous in reducing fracture risk. The sponsors' preliminary data indicate that loading-induced structural changes in cortical bone are maintained long-term and contribute to lifelong enhancement of bone strength. The current application will explore this further in three translational animal studies by investigating: (1) the short- and long-term preservation of loading benefits at both cortical and trabecular sites; (2) the influence of an artificial menopause (induced via ovariectomy) on the preservation of loading effects, and; (3) potential mechanisms for the maintenance or loss of loading-induced changes. In each study, bone adaptation will be induced in the right forelimb or hindlimb of young rats using the ulna or tibial axial loading models, respectively. Left limbs will serve as nonloaded, internal controls. Animals will subsequently be detrained (restricted to cage activities) for 12, 18 or 92 wks, with ovariectomy being performed in some animals to induce an artificial menopause. Bone response to loading and detraining will be assessed using a combination of in vivo and ex vivo analyses. To complement these animal studies, a fourth clinical study will be performed in which throwing athletes will be explored as a potential human model for the lifelong skeletal benefits of exercise during growth. This later study will provide preliminary data for future clinical studies on this topic. PUBLIC HEALTH RELEVANCE: A commonly prescribed treatment for the increased risk for osteoporotic fracture associated with aging is exercise. However, the skeleton is most responsive to exercise around the time of puberty, and not when it is prone to osteoporotic fracture in later adulthood. This has raised the question of whether exercise-induced bone changes during growth persist into adulthood where they would be most advantageous in reducing bone fracture risk. This application will investigate the role of exercise during growth on long-term skeletal health.