Effects of Multi-axial Whole Body Vibrations on Postural Stability

摘要 职业重型设备车辆操作工的职业伤害发生率很高 和疾病。在所有伤害中，与车辆进出时跌倒有关的伤害占 在美国，致命和非致命伤害的比例都很高。这些与跌倒相关的伤害的比率一直是 与车辆进入时相比，出口时的费用要高得多(高达8倍)。一个可能的原因是 在出口过程中，与跌倒相关的不成比例的高伤害率是姿势稳定性的丧失。长期接触 全身振动(WBV)损害了姿势的稳定性，因此会增加跌倒的风险。关闭- 道路重型设备车辆操作员尤其面临更大的风险，因为他们暴露在更高的 与道路车辆运营商相比，WBV的水平。此外，主要的WBV曝光轴在 越野重型装备车辆不一定局限于垂直(z轴)，但往往可以包括 重要的纵向(x轴)和/或横向(y轴)组件。多轴附加影响的性质 WBV暴露对体位稳定性的影响目前知之甚少。此外，缺乏科学研究。 评估有效的工程干预措施，以减少车辆运行过程中的多轴暴露。 我们建议进行一项重复测量的实验室研究，以确定单一和多个因素的相对影响。 轴向WBV暴露对姿势稳定性的影响，并确定一种新发明的创新效果 工程控制，以减少多轴WBV暴露和相关的体位不稳定性。WBV暴露 将在实验室中通过复制越野重型车辆的实际现场测量的振动剖面来模拟 在运动平台上装备车辆。确定多轴WBV暴露是否会有更大的 对姿势稳定性的影响与垂直占优势的WBV相比，我们将评估稳定性的功能极限， 站立平衡时的姿势稳定性，以及功能任务之前的预期姿势调整，如 水平步态和楼梯下降。我们还将测试使用多轴悬挂式座椅是否会缓解 多轴WBV对姿势稳定性措施的不良影响比单轴被动更有效 吊椅。该项目的结果可以支持未来减少与跌倒相关的伤害和 从而提高越野车操作者的职业健康幸福感。该项目支持 NIOSH国家职业研究议程，特别是运输和采矿部门，以及 肌肉骨骼健康研究优先事项(非-OH-16-012)，通过明确描述以下物质的相对影响 单轴和多轴WBV暴露对越野车辆操作员姿势稳定性的影响 WBV的类型和程度与跌倒相关伤害的风险之间的神经生理学基础，以及 评估可有效减少暴露于多轴WBV的创新工程控制措施。

Abstract Professional heavy equipment vehicle operators suffer from a high prevalence of occupational injuries and illnesses. Among all injuries, fall-related injuries during vehicle ingress and egress have accounted for a large proportion of both fatal and non-fatal injuries in the US. The rate of these fall-related injuries has been much higher (up to 8 times) during egress as compared to ingress of vehicles. A likely cause for the disproportionally high fall-related injury rates during egress is a loss of postural stability. Prolonged exposure to Whole Body Vibration (WBV) compromises postural stability and thereby can increase the risks of falling. Off- road heavy equipment vehicle operators are particularly at a greater risk, because they are exposed to a higher level of WBV as compared to on-road vehicle operators. Furthermore, the predominant WBV exposure axis in off-road heavy equipment vehicles is not necessarily limited to the vertical (z-axis), but can often include significant fore-aft (x-axis) and/or lateral (y-axis) components. The nature of the additional impact of multi-axial WBV exposure on postural stability is poorly understood at present. Moreover, there is a lack of scientific studies to evaluate effective engineering interventions to mitigate multi-axial exposures during vehicle operation. We propose a repeated-measures laboratory study to identify the relative impacts of single- and multi- axial WBV exposure on postural stability, and to determine the effectiveness of a newly-invented innovative engineering control to mitigate multi-axial WBV exposure and associated postural instability. WBV exposures will be simulated in the laboratory by replicating actual field-measured vibration profiles from off-road heavy equipment vehicles on a motion platform. To determine whether multi-axial WBV exposure will have a greater impact on postural stability compared to vertical-dominant WBV, we will assess functional limits of stability, postural stability in standing balance, and anticipatory postural adjustments preceding functional tasks such as level gait and stair descent. We will also test whether the use of a multi-axial suspension seat will alleviate the adverse effects of multi-axial WBV on postural stability measures more effectively than a single-axial passive suspension seat. Results of this project can support future efforts to reduce the risks of fall-related injuries and therefore improve the occupational health and well-being for off-road vehicle operators. This project supports the NIOSH National Occupational Research Agenda, especially for the transportation and mining sectors, and the Musculoskeletal Health Research Priorities (NOT-OH-16-012), by clearly delineating the relative impacts of single- and multi-axial WBV exposures on postural stability among off-road vehicle operators, providing the neurophysiological underpinnings relating the type and extent of WBV with the risk of fall-related injuries, and by evaluating innovative engineering controls that may effectively reduce exposure to multi-axial WBV.