The Sensorimotor Locus of Balance Control in Elderly Gait

我们的老龄化人口是在一个非常高的风险，使人衰弱的福尔斯，大大有助于减少 独立性和生活质量。尽管有传统的诊断和康复努力，三分之一的人 65岁以上的人每年都会跌倒，其中20-30%的福尔斯会导致中度至重度损伤。值得注意的是， 表明老年人中受伤性福尔斯的比率正在加速。通过创新的感觉运动 范例使用光流扰动在自定义虚拟环境中，该建议旨在解决 迫切需要变革性的新方法来识别和减轻我们的福尔斯风险， 人口老龄化我们的首要目标是研究光流扰动的有效性，特别是 当在步行过程中应用时，以：（i）阐明老化和福尔斯历史对站立和步行平衡的影响 控制，以及（ii）随后通过培训条件成功的平衡控制策略。第一个目标将 紧密集成虚拟现实，视觉诱导（即，运动反应的本能同步 视觉刺激），以及一系列临床和自我报告的基准，以调查衰老和福尔斯史 在站立和行走期间对光流扰动的响应的影响。我们将检验这个假设 在行走过程中的光流扰动将区分年龄和福尔斯历史更有效地比那些 在站立和效果大小大于那些从传统的平衡测试。第二个目标将 研究控制光流敏感性的感觉、运动和认知运动机制 扰动使用策略性选择的结果测量和多变量建模的组合，我们 将测试这一假设，即夹带光流扰动将最强烈地与视觉 依赖和躯体感觉功能下降，暗示着与年龄相关的多感觉过程 在行走中最显著的变化。最后，我们的第三个目标是获得初步的 深入了解长期光流扰动的功效，以成功地调节用于 控制老年跌倒者的行走平衡。在一项随机交叉设计中， 福尔斯将完成两个跑步机训练阶段-一个是（即，“训练”阶段）和一个没有（即， “控制”会话）动态光流扰动。我们将验证一个假设，即有病史的老年人 的福尔斯将适应长时间暴露于扰动，调节他们在行走中的一步一步调整 平衡控制和提高他们对训练后意外平衡挑战的反应。本研究 代表了一个跨学科的合作，涉及经验丰富的研究人员在生物医学工程， 物理治疗和运动控制R21的成功完成将提供必要的机制 以及设计大型诊断和干预研究所需的初步疗效信息， 扰动光流减轻跌倒风险的价值和适用性。随着可穿戴和低成本技术的出现， 成本虚拟现实技术，这一建议是及时和临床可行的。

Our aging population is at an exceptionally high risk of debilitating falls, contributing significantly to reduced independence and quality of life. Despite conventional diagnostic and rehabilitative efforts, one-third of people over age 65 fall annually and 20-30% of these falls lead to moderate to severe injury. Remarkably, evidence even suggests that the rate of injurious falls among older adults is accelerating. Through an innovative sensorimotor paradigm using optical flow perturbations in a custom virtual environment, this proposal seeks to address the critical and immediate need for transformative new approaches for identifying and mitigating falls risk in our aging population. Our overarching goal is to investigate the efficacy of optical flow perturbations, particularly when applied during walking, to: (i) elucidate aging and falls history effects on standing and walking balance control, and (ii) subsequently condition successful balance control strategies through training. The first aim will tightly integrate virtual reality, visuomotor entrainment (i.e., the instinctive synchronization of motor responses to visual stimuli), and a series of clinical and self-reported benchmarks to investigate aging and falls history effects on the response to optical flow perturbations during standing and walking. We will test the hypothesis that optical flow perturbations during walking will distinguish age and falls history more effectively than those during standing and with effect sizes larger than those from conventional balance testing. The second aim will investigate sensory, motor, and cognitive-motor mechanisms governing susceptibility to optical flow perturbations. Using a strategically-selected combination of outcome measures and multivariate modeling, we will test the hypothesis that entrainment to optical flow perturbations will correlate most strongly with visual dependence and decreased somatosensory function, alluding to an age-associated process of multi-sensory reweighting that will emerge most prominently in walking. Finally, our third aim is designed to gain preliminary insight into the efficacy of prolonged optical flow perturbations to condition strategies used to successfully control walking balance in older adult fallers. In a randomized cross-over design, older adults with a history of falls will complete two treadmill training sessions – one with (i.e., “training” session) and one without (i.e., “control” session) dynamic optical flow perturbations. We will test the hypothesis that older adults with a history of falls will adapt to prolonged exposure to perturbations, conditioning their step to step adjustments in walking balance control and improving their response to unexpected balance challenges following training. This research represents an interdisciplinary collaboration involving experienced investigators in biomedical engineering, physical therapy, and motor control. Successful completion of this R21 will provide the necessary mechanistic and preliminary efficacy information needed to design larger diagnostic and intervention studies to determine the value and applicability of perturbed optical flow to mitigate fall risk. With the advent of wearable and low cost virtual reality technology, this proposal is both timely and clinically feasible.