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，了解不稳定的确切原因是必要的。已知加剧不稳定和跌倒风险的一个因素是不活动，这种情况往往会随着年龄的增长而增加。这种不活动的趋势由于与年龄有关的疾病而加剧，这往往导致长时间的深度不活动，无论是在家里还是在医院的病床上。虽然已知这种不活动会损害姿势控制，但我们不了解确切的机制。这个项目的目的是检查长时间不活动对姿势控制的影响。我们将对年轻健康受试者在长时间卧床休息（60天）前后进行研究。通过对年轻人的研究，我们将获得不运动如何影响姿势的纯粹理解，而不考虑与年龄相关的混淆合并症。我们将使用称为前庭电刺激（GVS）的技术来评估姿势控制。GVS引起站立受试者的摇摆反应，可用于测试平衡系统的有效性。我们将在长时间卧床休息之前和之后立即检查GVS反应，以确定反应如何变化。摆动响应的幅度和精度将分别进行分析。任何幅度的减少，或反应方向准确性的变化，都表明姿势控制受损。确定这些问题将为不活动后恢复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.