Effect of prolonged inactivity on vestibular control of balance

姿势不稳和跌倒是老年人的主要问题，导致受伤和死亡率增加。在我们实施有针对性的治疗方案或改变生活方式之前，有必要了解导致不稳定的确切原因(S)。已知的加剧不稳定和跌倒风险的一个因素是缺乏运动，这种情况往往会随着年龄的增长而增加。这种不活动的趋势因与年龄有关的发病率而加剧，这往往导致在家中或在医院病床上长时间严重不活动。虽然已知这种不活动会损害姿势控制，但我们并不了解其确切的机制。这个项目的目的是检查长期不活动对姿势控制的影响。我们将研究长期卧床(60天)前后的年轻健康受试者。通过对年轻人的研究，我们将对不运动如何影响姿势有一个纯粹的理解，而不会出现与年龄相关的令人困惑的共病。我们将使用一种名为电流前庭刺激(GVS)的技术来评估姿势控制。GVS在站立受试者中引起摇摆反应，可用于测试平衡系统的有效性。我们将检查长时间卧床之前和之后的GVS反应，以确定反应是如何变化的。摇摆响应的幅度和精确度将分别进行分析。任何幅度的降低，或反应方向准确性的变异性，都将表明姿势控制受损。识别这些问题将为恢复静止后的姿势控制提供治疗目标。

Postural instability and falls are a major problem in older adults, leading to injuries and increased mortality. Understanding the precise cause(s) of instability is necessary before we can implement targeted therapy programmes or lifestyle changes. One factor known to exacerbate instability and fall risk is inactivity, which tends to increase with age. This tendency towards inactivity is compounded by age-related morbidity, which often results in extended periods of profound inactivity, either in the home or in a hospital bed. Although such inactivity is known to impair postural control, we do not understand the precise mechanisms. The purpose of this project is to examine the effect of prolonged inactivity upon postural control. We will study young healthy subjects before and after a prolonged period of bed rest (60 days). By studying young adults, we will gain a pure understanding of how inactivity affects posture without the confounding co-morbidities associated with age. We will assess postural control using a technique called galvanic vestibular stimulation (GVS). GVS causes a sway response in standing subjects and can be used to test the efficacy of the balance system. We will examine GVS responses immediately before and after prolonged bed rest to determine how the response changes. The amplitude and accuracy of the sway response will be analysed separately. Any reduction in amplitude, or variability in the directional accuracy of the response, would indicate impaired postural control. Identifying such problems will provide therapeutic targets for recovery of postural control following inactivity.