Lateral Stability and Falls in Aging

描述（由申请人提供）：本研究的长期目标是确定老年人姿势平衡功能障碍背后的神经力学（NM）损伤机制，并建立科学基础的治疗方案，以增强平衡功能和降低跌倒风险。当人的平衡受到挑战时，踏步反应是稳定身体和防止跌倒的有力手段。因此，在日常生活活动中，保护性行走是保持平衡的重要策略。我们认为，老化限制了局部髋关节中外侧（M-L）外展/内收（AB/AD） NM反应，通过破坏保护性步进损害了侧平衡稳定性。因此，许多老年人可能特别容易发生侧位不稳和伤害性跌倒。因此，我们的目标包括实验、建模和介入方法来理解这些关系。目标一是a)确定平衡扰动水平，在该水平上，由于运动动力学和运动学决定的髋关节AB/AD NM控制的限制，老年受试者过渡到更危险和更有问题的交叉保护步进模式；b)评估平衡扰动程度和相关的踏步和髋关节AB/AD NM反应措施是否能区分低跌倒风险受试者和高跌倒风险受试者。目标二是开发和应用一个计算模型，预测与区域髋关节AB/AD NM限制相关的M-L步进模式的平衡极限。目的三是评估必要的可行性因素（依从性、耐受性、益处），以推进预防跌倒的全面治疗干预。我们假设，将诱导步进训练和髋关节AB/AD肌肉强化相结合的干预方法将比单独进行任何一项计划更能改善运动成绩，并且减少预期的跌倒。公共卫生相关性。这项研究与公共卫生的相关性在于其重点在于了解与年龄有关的跌倒的原因和干预措施，以尽量减少破坏性的经济、社会和个人后果。

DESCRIPTION (provided by applicant): The long term objectives of this research are to identify the mechanisms of neuromechanical (NM) impairments underlying postural balance dysfunction in older people, and to establish a scientifically grounded therapeutic program for enhancing balance function and reducing the risk of falls. When human balance is challenged, the stepping reaction is a powerful means of stabilizing the body and preventing falling. Protective stepping is therefore a vital strategy for maintaining balance during activities of daily life. We propose that aging limitations in regional medio-lateral (M-L) hip abductor/adductor (AB/AD) NM responses compromise lateral balance stability by disrupting protective stepping. Consequently, many older people may be particularly vulnerable to lateral instability and injurious falls. Accordingly, our aims involve experimental, modeling, and interventional approaches to understanding these relationships. Aim one is to a) identify the balance perturbation magnitude level at which older subjects transition to a riskier and more problematic crossover protective stepping pattern due to limitations in hip AB/AD NM control as determined by movement kinetics and kinematics; and to b) assess whether balance perturbation magnitude and associated stepping and hip AB/AD NM response measures discriminate between subjects with low fall risk and those with high fall risk. Aim two is to develop and apply a computational model that predicts the balance limits of M-L stepping patterns in relation to regional hip AB/AD NM limitations. Aim three is to assess feasibility factors (compliance, tolerance, benefits) necessary to advance a full-scale therapeutic intervention for preventing falls. We hypothesize that an intervention approach that combines induced step training and hip AB/AD muscle strengthening will demonstrate greater improvements in performance outcomes and fewer prospectively identified falls than either program performed alone. PUBLIC HEALTH RELEVANCE. The relevance of this research to public health lies in its focus on understanding the causes and interventions for minimizing the devastating economic, societal, and personal consequences of age-associated falls.