Biomechanics of slips in older adults

描述（由申请人提供）：由外部扰动（如滑倒、绊倒和绊倒）引发的福尔斯对老年工人的健康构成严重危害。实验研究已经提供了对扰动的姿势反应的一般描述。然而，由于姿势控制系统的复杂性和关键步态变量之间的显著相关性，仅通过实验来解开失败的恢复尝试的原因具有挑战性。在滑倒过程中姿势反应的正向模拟将与实验数据结合使用，以确定特定于受试者的生物力学限制，解释为什么老年人滑倒。更具体地说，我们将确定滑移的大小取决于随年龄变化的步态变量的程度，包括步长和质心加速度（目标1），力量和扭矩产生率能力（目标2）。最后，在目标3中，我们将使用具有解释变量的多元回归模型预测滑动的幅度，这些解释变量（1）在模拟中已被确定为降低滑动和福尔斯风险的关键变量，以及（2）可以在非光滑环境中测量。为了收集实现本项目目标所需的实验数据，将招募107名（N = 107）年龄在55岁至70岁之间的老年人参与。受试者将在干燥和湿滑的地板上行走。将收集两个年龄组的强度数据。模拟将基于受试者特定的身体模型，由生理激励控制器产生的扭矩驱动。与公共卫生的相关性：总之，通过实验和模拟滑倒，本项目将系统地识别与年龄相关的生物力学限制，使老年工人更容易滑倒。这些生物力学限制可能是神经肌肉控制和感觉整合的潜在缺陷的结果，但它们是从外部扰动中恢复失败的最终原因。需要这些基本知识来规划、制定和实施有效的针对赤字的干预措施，重点是最大限度地减少在工作场所跌倒的风险。

DESCRIPTION (provided by applicant): Falls initiated by external perturbations such as slips, trips and stumbles are a serious health hazard to older workers. Experimental studies have provided a general description of postural responses to perturbations. However, causes of failed recovery attempts are challenging to disentangle through experiments alone due to the complexity of the postural control system and the significant degree of correlation among key gait variables. Forward simulations of postural responses during slipping will be used in conjunction with experimental data to identify subject-specific biomechanical limitations that explain why older adults slip and fall. More specifically, we will determine the extent to which the magnitude of the slip depends on gait variables that change with aging including step length and center of mass acceleration (Aim 1), strength and torque generation rate abilities (Aim 2). Finally in Aim 3, we will predict the magnitude of a slip using a multi- regression model with explanatory variables that (1) have been identified in the simulations as key variables to reduce the risk of slips and falls, and (2) can be measured in non-slippery environments. To collect the experimental data required to achieve the aims of this project, one hundred seven (N = 107) older adults between the ages of 55 and 70 years old will be recruited for participation. Subjects will walk on dry and slippery floors. Strength data will be collected in both age groups. Simulations will be based on subject- specific models of the body driven with torques generated by a physiologically motivated controller. Relevance to public health: In summary, through experiments and simulations of slipping, this project will systematically identify aging-related biomechanical limitations that predispose older workers to slip and fall. These biomechanical limitations may be the result of underlying deficits in neuromuscular control and sensory integration but they are the ultimate cause of failed recoveries from external perturbations. This fundamental knowledge is required to plan, to develop and to implement effective deficits-targeted interventions focused on minimizing the risk of falling in the workplace.