Age-related changes in multi-behavioral reactive balance control

项目摘要 我们的长期目标是提高对多行为感觉运动神经系统中与年龄相关的变化的认识， 控制导致老年人福尔斯跌倒的平衡，以指导开发更有效的治疗方法， 康复，改善平衡。尽管传统的诊断和康复努力，我们的快速老化， 人口仍然处于衰弱性福尔斯的高风险中。这些福尔斯可以发生在各种不同的运动 日常生活中重要的行为，包括站立、从椅子上起身和行走。当失去平衡时 如果在任何这些运动行为中发生，肌肉必须反应性地恢复身体， 直立以防止跌倒。肌肉应该如何招募取决于平衡损失的大小 (e.g.,小对大）以及当平衡损失发生时一个人正在做什么（例如，站立与 步行）。反应性肌肉募集的调节如何受衰老的影响，以及与 下落不明。因此，作为我们迈向长远目标的第一步，拟议项目的目标是 为了确定在福尔斯经常发生的几种运动行为中反应性肌肉募集的变化， 发生在老年人中-站立，坐立和行走。研究反应性肌肉的变化 招聘，我们将实验性地施加平衡损失，通过离散平移的支持面 (i.e.扰动），同时使用 来自一组年轻人、老年人和有跌倒史的老年人的肌电图。在 具体目标1，我们将研究反应性肌肉募集的缩放如何由于衰老和衰老而改变。 福尔斯的历史。缩放是指在单个运动中调节反应性肌肉募集的能力 行为与扰动的大小相关（例如，更大的扰动需要更高水平的反应性肌肉 为防止跌倒而进行的招聘）。缩放将在站立、坐立和行走中独立进行研究 通过让受试者接受不同难度的扰动在具体目标2中，我们将研究 反应性肌肉募集的调节由于老化和福尔斯史而改变。调优是指能够 调节不同运动行为中的反应性肌肉募集（例如，脚踝肌肉应该如何 是否被招募取决于平衡的丧失是否发生在站立和行走中）。调优将被调查 通过检查三种运动行为中每一种的反应性肌肉募集的差异。 该项目的成果将加强我们对多方面变化的基本理解， 由于衰老引起的与跌倒史相关的行为反应性肌肉募集-这些变化可能 作为康复干预的目标，以改善平衡。此外，拟议项目还将 为西弗吉尼亚大学的本科生提供生物力学和运动控制研究的培训机会， 为他们在未来的研究生涯中取得成功奠定了坚实的基础。

PROJECT SUMMARY Our long-term goal is to advance knowledge on age-related changes in the multi-behavioral sensorimotor control of balance leading to falls in older adults to guide the development of more effective treatments and rehabilitation for improving balance. Despite conventional diagnostic and rehabilitative efforts, our rapidly aging population remains at a high risk of debilitating falls. These falls can occur in a variety of different movement behaviors important for daily life, including standing, arising from a chair, and walking. When a loss of balance occurs during any of these movement behaviors, muscles must be reactively recruited to return the body upright in order to prevent a fall. How muscles should be recruited depends on the size of the balance loss (e.g., small versus large) and what a person is doing when the balance loss occurs (e.g., standing versus walking). How the modulation of reactive muscle recruitment is affected by aging and associated with risk of falling is unknown. As a first step towards our long-term goal, the objective of the proposed project is therefore to identify changes in reactive muscle recruitment across several movement behaviors in which falls often occur in older adults – standing, sit-to-stand, and walking. To investigate changes in reactive muscle recruitment, we will experimentally impose balance loss through discrete translations of the support surface (i.e. perturbation) during each of these movement behaviors while measuring muscle activity using electromyography from a group of young adults, older adults, and older adults with a history of falling. In Specific Aim 1, we will investigate how scaling of reactive muscle recruitment is altered due to aging and a history of falls. Scaling refers to the ability to modulate reactive muscle recruitment within a single movement behavior to the size of the perturbation (e.g., larger perturbations require higher levels reactive muscle recruitment to prevent a fall). Scaling will independently be investigated in standing, sit-to-stand, and walking by exposing subjects to various levels of perturbation difficulty. In Specific Aim 2, we will investigate how the tuning of reactive muscle recruitment is altered due to aging and a history of falls. Tuning refers to the ability to modulate reactive muscle recruitment across different movement behaviors (e.g., how ankle muscles should be recruited depends on if the loss of balance occurs in standing versus walking). Tuning will be investigated by examining the differences in reactive muscle recruitment across each of the three movement behaviors. The outcomes of this project will enhance our fundamental understanding regarding changes in multi- behavioral reactive muscle recruitment due to aging that are associated with fall history – changes which could serve as targets for rehabilitation interventions to improve balance. In addition, the proposed project will also provide undergraduate students at WVU training opportunities in biomechanics and motor control research, providing a strong basis for their success in their future research careers.