Minimizing Instability with Dynamic Visual Inputs

描述（由申请人提供）：该项目的长期目标是了解如何通过使用动态视觉环境来帮助平衡和步态障碍，以促进运动和站立姿势控制期间的感觉运动再学习。当前庭输入变得不可靠时，无论是由于前庭功能丧失还是功能障碍，个体必须学会依靠视觉和本体感受通路来对姿势方向或平衡的变化产生适当的反应。通过在静态环境中练习姿势和有目的的活动来产生感觉再学习的尝试并没有被证明是完全成功的干预，这可能是因为受控输入对姿势系统的功能没有必要的要求。个体可能会固定在一种反应模式上，无法与环境中遇到的干扰范围相匹配。我们建议研究在动态视觉环境中的正常人和患者的双侧肾上腺素损失的运动过程中的姿势反应和空间方向的变化。我们假设，前庭损失的个人成为固定在一个战略的补偿，不能补偿的波动需求的动态环境。我们将研究是否提供使用视觉信息的策略，帮助这些人在补偿不稳定。受试者将在安静的站立和在跑步机上行走时进行测试，同时我们操纵动态虚拟环境的速度或上下文对比度。将测量节段性偏移和压力中心，并使用重复测量ANOVA进行分析，以确定姿势组织和方向是否受周边视野特定参数的影响。出现最不稳定的参数将被应用于训练计划，其中受试者将被指示专注于远处的目标或内部反馈，以确定在动态视觉环境中的主动表现是否增加了具有谷胱甘肽损失的个体的反应库。最后，我们将评估在动态视觉环境中训练是否有功能遗留。受试者将执行一个模拟的物理世界的任务，他们必须检索和放置一个对象，而世界在他们周围移动，障碍物出现在他们的path.Results从这些研究将提供洞察动态的visualvestibular相互作用，并确定具体的定量协议的治疗干预与平衡障碍。

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand how balance and gait disorders can be helped by using dynamic visual environments to facilitate sensorimotor relearning during locomotion and stance postural control. When vestibular inputs become unreliable, either from labyrinthine loss or dysfunction, individuals must learn to rely upon visual and proprioceptive pathways to produce appropriate responses for changes in postural orientation or equilibrium. Attempts to produce sensory relearning through practicing postural and purposeful activities in static environments have not proved to be a fully successful intervention, possibly because the controlled inputs do not place the necessary demands on the functionality of the postural system. Individuals may become fixed on one pattern of response and be unable to match the range of disturbances encountered in the environment. We propose to study changes in postural responses and spatial orientation during locomotion within a dynamic visual environment in normal subjects and in patients with bilateral labyrinthine loss. We hypothesize that individuals with vestibular loss become fixed on one strategy of compensation and cannot compensate for the fluctuating demands of a dynamic environment. We will examine whether providing strategies for using visual information assists these individuals in compensating for destabilization. Subjects will be tested during quiet stance and walking on a treadmill while we manipulate the velocity or contextual contrast of a dynamic virtual environment. Segmental excursions and center of pressure will be measured and analyzed with repeated measures ANOVAs to determine if postural organization and orientation is influenced by specific parameters of the peripheral field of view. The parameters that emerge as most destabilizing will be applied in a training program where subjects will be instructed to focus on a distant target or on internal feedback to determine if active performance in a dynamic visual environment increases the response repertoire of individuals with labyrinthine loss. Finally, we will assess whether there is functional carryover from training within a dynamic visual environment. Subjects will perform a simulated physical world task in which they must retrieve and place an object while the world moves around them and obstacles appear in their path. Results from these studies will provide insight into the dynamics of the visualvestibular interaction and identify specific quantitative protocols for therapeutic interventions with balance disorders.