The Sensorimotor Locus of Balance Control in Elderly Gait

我们老龄化的人口面临着极高的跌倒风险，这对 独立性和生活质量。尽管采取了传统的诊断和康复措施，但仍有三分之一的人 65岁以上的人每年都会跌倒，其中20%-30%的跌倒会导致中到严重的伤害。值得注意的是，甚至有证据表明 这表明老年人的伤害性跌倒速度正在加快。通过一种创新的传感器马达 在定制虚拟环境中使用光流扰动的范例，该建议试图解决 迫切需要变革性的新方法来识别和降低我们的 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 当在行走中应用时，用来：(I)阐明衰老和跌倒病史对站立和行走平衡的影响 控制，以及(Ii)随后通过培训为成功的平衡控制策略创造条件。第一个目标是 将虚拟现实、视觉运动夹带(即运动反应的本能同步)紧密结合在一起 视觉刺激)，以及一系列临床和自我报告的基准来调查衰老和跌倒病史 站立和行走时对光流扰动响应的影响。我们将检验这一假设 步行过程中的光流扰动将更有效地区分年龄和跌倒历史 站立时的有效尺寸比常规平衡测试的尺寸大。第二个目标是 研究影响光流敏感性的感觉、运动和认知运动机制 微扰。使用经过战略选择的结果测量和多变量建模的组合，我们 将检验这样的假设，即卷吸对光流扰动的影响将与视觉最密切相关 依赖和躯体感觉功能下降，暗指与年龄相关的多感觉过程 重新调整权重，这将在步行中最突出地出现。最后，我们的第三个目标是初步获得 洞察长期光流扰动的有效性，以适应成功使用的策略 控制老年人跌倒者的行走平衡。在随机交叉设计中，有高血压病史的老年人 福尔斯将完成两个跑步机训练课程--一个有(即，训练)课程，另一个没有(即， 控制会话)动态光流扰动。我们将检验这样一种假设：有病史的老年人 跌倒的人会适应长时间暴露在干扰中，调节他们在走路时的步幅调整 平衡控制和提高他们在训练后对意外平衡挑战的反应。这项研究 代表着涉及生物医学工程领域经验丰富的研究人员的跨学科合作， 理疗和运动控制。R21的成功完成将提供必要的机械 以及设计大型诊断和干预研究所需的初步疗效信息，以确定 摄动光流法降低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，这一建议具有时效性和临床可行性。

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.