Protective Balance and Startle Responses to Sudden Drop Perturbations in Aging

对衰老过程中突然下降的扰动的保护性平衡和惊吓反应

• 批准号: 8977326
• 负责人: MARK W ROGERS
• 金额: $ 23.03万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8977326
• 关键词: Acoustics; Acute; Advance Directives; Affect; Age; Aging; Awareness; Brain Stem; Caring; Clinical; Communities; Development; Drops; Economics; Effectiveness; Elderly; Equilibrium; Event; Fall prevention; Force of Gravity; Future; Healthcare; Home environment; Human; Individual; Injury; Intervention; Joints; Limb structure; Link; Measures; Medical; Modeling; Motion; Motor; Movement; Muscle; Outcome; Pattern; Peripheral; Postural response; Process; Public Health; Quality of life; Reaction; Recovery; Rehabilitation therapy; Research; Residual state; Sensory; Startle Reaction; Stimulus; Surface; System; Testing; Therapeutic Intervention; Time; Training; age related; base; behavioral habituation; design; effective intervention; equilibration disorder; fall risk; falls; habituation; kinematics; limb movement; multisensory; neuromuscular; neurophysiology; novel; novel therapeutic intervention; public health relevance; response; somatosensory; sound

 DESCRIPTION (provided by applicant): Falls and their consequences are among the major problems in the medical care of older individuals. Our central hypothesis is that age-associated abnormalities of excessive and poorly habituated startle/postural FTRs increase fall risk and related injuries by interfering with effective postural movements through excessive muscle responses and joint stiffening, and by increasing injurious fall impact forces, or both. However, such abnormalities with older age may be modified through residual startle plasticity capacity. During sudden imbalance, unexpected postural disturbances resemble startling events that may precipitate a fall. The excessive startle-like reaction incorporated into the first trial postural response (FTR) normally diminishes with habituation. Because all falls include downward motion of the body with gravity that may trigger a startle, understanding whether the FTR during sudden drop perturbations either enhances protective balance recovery or is problematic for it would be important to determine. Furthermore, whether the FTR is changed with aging would also be essential to know because both balance and startle show age-related abnormalities. Moreover, identifying ways to therapeutically normalize abnormal startle contributions to FTRs with aging by determining the modulatory influences such as behavioral habituation, subject awareness through motor prediction (central set) that normally modifies startle responses, or through a sensory prestimulus before the drop perturbation (prestimulus inhibition) would be important to identify. Whole body postural muscle activation patterns, movement kinematics, and landing impact forces will be assessed by electromyographic (EMG) recordings, motion capture, and force platform recordings. The specific aims are 1) to determine the age-associated changes in neuromuscular and kinematic mechanisms affecting startle/postural FTRs and response habituation after externally-activated (reactive) drop perturbations of the standing support surface by measuring the timing and magnitude parameters indicative of impaired sensorimotor conduction and brainstem processing and integration of somatosensory and vestibular information with older age; and 2) To determine a) the modulatory effects of motor prediction in relation to older age on FTRs by comparing the whole-body startle/postural responses to reactive drop perturbations and self-activated (predictive) perturbations on FTRs and response habituation, and b) the modulatory effects of an acoustic prestimulus on the FTR magnitude and subsequent postural responses evoked by reactive drop perturbations. Expected outcomes are that abnormal neurophysiological mechanisms causing excessive startle contributions to postural FTRs with older age will be linked with impaired balance stability. Moreover, determining the acute modulatory influences on startle will be first steps in the development of novel future rehabilitation interventions to minimize disruptive FTR reactions and prevent falls and related injuries.

 描述（由适用提供）：跌倒及其后果是老年人医疗保健的主要问题。我们的核心假设是，与年龄相关的异常和习惯性不佳的惊吓/姿势FTRS通过过多的肌肉反应和关节僵硬，以及增加伤害性跌落撞击力或两者兼而有之，通过干扰有效的姿势运动，从而增加了跌落的风险和相关伤害。但是，这种年龄较大的异常可以通过残留的惊吓能力来改变。在突然失衡的过程中，意外的姿势灾难类似于可能导致跌倒的起始事件。纳入第一个试验的姿势反应（FTR）中，过量的惊吓样反应通常会随着习惯而减少。因为所有跌落都包括身体的向下运动，重力可能会引起惊吓，所以了解突然滴扰动中的FTR是否会增强保护性平衡的恢复，或者是有问题的，因为确定很重要。此外，由于平衡和惊吓与年龄相关的异常，FTR是否随着衰老而改变也是必不可少的。此外，通过确定诸如行为习惯，通过运动预测（中央集合）的主题意识，通常会改变惊吓反应或通过感官prestimulus在下降（prestimulus抑制）之前，确定诸如行为习惯，通过运动预测的主题意识（中央集合）来确定对FTR的异常惊慌失措的方法，从而通过运动预测（中心设置）来确定衰老的异常贡献。全身姿势肌肉激活模式，运动运动学和着陆撞击力将通过肌电图（EMG）记录，运动捕获和力平台记录来评估。具体目的是1）确定影响惊吓/姿势FTR的神经肌肉和运动学机制的变化，以及在外部激活（反应性）站立支持表面的下降（反应性）下降（反应性）通过测量障碍的对启动性敏感性和脑系统处理的障碍参数，并通过测量时间和幅度参数，并进行了脑力集合和整合的整体。 and 2) To determine a) the modulatory effects of motor prediction in relation to older age on FTRs by comparing the whole-body Startle/postural responses to reactive drop perturbations and self-activated (predictive) perturbations on FTRs and response habituation, and b) the modulatory effects of an acoustic prestimulus on the FTR magnitude and subsequent postural responses evoked by reactive drop perturbations.预期的结果是，异常的神经生理机制，导致惊吓过度贡献的姿势FTR将与平衡稳定性受损有关。此外，确定对惊吓的急性调节影响将是开发新的未来康复干预措施的第一步，以最大程度地减少颠覆性的FTR反应并防止下降和相关伤害。