Hip Muscle Power, Lateral Balance Function, and Falls in Aging

项目摘要/摘要 跌倒及其后果是老年人医疗保健中的主要问题之一。 这项研究的长期目标是通过机制衍生的治疗干预来增强肌肉。 动力、重心转移能力和防止跌倒的侧向平衡。当人类的平衡受到挑战时， 在日常生活活动中，保护步法是防止跌倒的重要策略。许多老年人处于危险之中 对于瀑布来说，作为一种保护性的反应，成功地横跨在一边是有特别困难的 在横向保持平衡。我们认为，与年龄相关的侧向平衡功能下降是通过 神经肌肉和生物力学导致的与跌倒相关的重量转移和保护性步态障碍 髋外展肌-内收肌(AB-AD)肌肉发电的局限性。此外，我们假设这些 功能和神经运动损伤可以通过高速肌肉阻力力量训练来改善。 具体目标是：目的1.确定与年龄相关的神经肌肉和生物力学的变化 评价独立最大扭矩和功率对髋关节AB-AD肌群功能的影响 生产和神经肌肉激活模式。目的2.测定神经运动的衰老变化 臀部AB-AD肌群在腰部牵引侧步前负重转移阶段的表现 步法和自愿反应时间步法。目标3.建立第一线证据表明 髋关节AB-AD肌力神经运动损伤导致回避的假说衰老缺陷 生产可能是可逆的，我们将确定速度依赖的肌肉阻力功率的影响 训练(3次/周×10周)与力量训练在神经肌肉、生物力学和 功能性能结果。总体而言，这些研究将确定与年龄相关的神经运动机制 髋关节AB-AD肌肉能量产生异常，损害侧向重量转移、平衡稳定性和灵活性 功能。为速度依赖性力量训练相对于速度依赖性力量训练的优势建立第一条支撑线 力量训练对肌肉表现、保护性平衡和功能性活动的结果，将导致 未来的比较干预试验，以增强这些功能，并防止老年人跌倒。

Project Summary/Abstract Falls and their consequences are among the major problems in the medical care of older individuals. The long-term goal of this research is to a mechanistically derived therapeutic intervention to enhance muscle power, weight-shifting capability, and lateral balance to prevent falls. When human balance is challenged, protective stepping is a vital strategy for preventing a fall during activities of daily life. Many older people at risk for falls have particular difficulties with successfully stepping sideways as a protective response to loss of balance in the lateral direction. We propose that age-related declines in lateral balance function through impaired weight transfer and protective stepping linked with falls, result from neuromuscular and biomechanical limitations in hip abductor-adductor (AB-AD) muscle power generation. Moreover, we hypothesize that these functional and neuromotor impairments can be improved with high velocity muscle resistance power training. The specigic aims are: Aim 1. To determine the age-associated changes in neuromuscular and biomechanical performance of the hip joint AB-AD musculature by evaluating the isolated maximum torque and power production and neuromuscular activation patterns. Aim 2. To determine the aging changes in neuromotor performance of the hip AB-AD musculature during the pre-step weight transfer phase of waist-pull induced side stepping and voluntary reaction time stepping. Aim 3. To establish a first line of evidence showing that hypothesized aging deficits in sidestepping caused by neuromotor impairments in hip AB-AD muscle power production may be reversible, we will determine the effects of velocity dependent muscle resistance power training (3 x/week x 10 weeks) compared with strength training on neuromuscular, biomechanical, and functional performance outcomes. Overall, the studies will identify age-related neuromotor mechanisms of abnormal hip AB-AD muscle power production that impair lateral weight transfer, balance stability, and mobility function. Establishing a first line of support for the superiority of velocity dependent power training over strength training on muscle performance and protective balance and functional mobility outcomes, will lead to a future comparative intervention trial to enhance these functions and prevent falls in older adults.