Aging and selective sensorimotor strategies in the regulation of upright balance
Aging and selective sensorimotor strategies in the regulation of upright balance
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DOI：
10.1186/1743-0003-4-19
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发表时间：
2007-06-20
影响因子：
5.1
通讯作者：
Fung, Joyce
中科院分区：
文献类型：
--
作者：
Bugnariu, Nicoleta;Fung, Joyce
背景：直立平衡的维持本质上是一种感觉运动整合任务。中枢神经系统（CNS）必须基于来自多个来源的感觉信息的选择性和快速整合来产生适当的和复杂的运动反应。由于每个感觉系统都有自己的坐标框架，特定的时间延迟和可靠性，可能会出现感觉冲突，并表示CNS必须重新校准归因于每个特定感觉输入的权重的情况。鉴于许多姿势调节系统（包括肌肉骨骼和感觉系统以及神经处理和信息传导）的完整性与年龄相关地下降，感觉冲突的解决可能对老年人来说是一个特殊的挑战。老化和适应的影响（通过反复曝光）的中枢神经系统的能力，以选择相关的感觉信息和解决感官冲突，从而调查与虚拟现实（VR）在本study.Methods：健康的年轻人和老年人保持安静的立场，而沉浸在虚拟环境（VE）为1小时，在此期间，短暂的视觉和/或表面扰动随机提出。视觉扰动是由通过头盔安装的显示器观察的VE的突然俯仰或滚转平面倾斜引起的，并且与或不与在与视觉扰动相同或相反的方向上呈现的表面扰动相结合。结果表明，衰老对通过肌电（EMG）反应和压力中心（COP）位移测量的姿势调整产生深远影响和身体的质心（COM）在恢复直立的立场，特别是在存在的感觉冲突。与年轻人相比，老年人更依赖视觉。衰老影响了躯体感觉和视觉系统之间的相互作用，影响了站立时的平衡控制和中枢神经系统解决感觉冲突的能力。然而，即使有一个小时的浸泡在VE和接触到的感觉冲突，它是可能的中枢神经系统重新校准和适应的变化，同时提高平衡能力在老年aduls.Conclusion：预防和康复计划，针对姿势控制在老年人应考虑到可能损害的感觉组织或感觉运动整合，包括VE训练条件下的感觉冲突。
Background: The maintenance of upright equilibrium is essentially a sensorimotor integration task. The central nervous system ( CNS) has to generate appropriate and complex motor responses based on the selective and rapid integration of sensory information from multiple sources. Since each sensory system has its own coordinate framework, specific time delay and reliability, sensory conflicts may arise and represent situations in which the CNS has to recalibrate the weight attributed to each particular sensory input. The resolution of sensory conflicts may represent a particular challenge for older adults given the age- related decline in the integrity of many postural regulating systems, including musculoskeletal and sensory systems, as well as neural processing and conduction of information. The effects of aging and adaptation ( by repeated exposures) on the capability of the CNS to select pertinent sensory information and resolve sensory conflicts were thus investigated with virtual reality ( VR) in the present study.Methods: Healthy young and older adults maintained quiet stance while immersed in a virtual environment ( VE) for 1 hour during which transient visual and/ or surface perturbations were randomly presented. Visual perturbations were induced by sudden pitch or roll plane tilts of the VE viewed through a helmet- mounted display, and combined with or without surface perturbations presented in a direction that was either identical or opposite to the visual perturbations.Results: Results showed a profound influence of aging on postural adjustments measured by electromyographic ( EMG) responses and displacements of the center of pressure ( COP) and body's center of mass ( COM) in the recovery of upright stance, especially in the presence of sensory conflicts. Older adults relied more on vision as compared to young adults. Aging affects the interaction of the somatosensory and visual systems on the control of equilibrium during standing and the ability of CNS to resolve sensory conflicts. However, even with a one- hour immersion in VE and exposure to sensory conflicts, it is possible for the CNS to recalibrate and adapt to the changes, while improving balance capability in older adults.Conclusion: Preventive and rehabilitation programs targeting postural control in older adults should take into account the possible impairment of sensory organization or sensorimotor integration and include VE training under conditions of sensory conflicts.