Locomotor Response of Persons with Upper Limb Loss to Treadmill Perturbations

这项初步研究的主要目的是表征退伍军人的主动和反应性运动反应 在行走过程中由于绊倒而失去上肢（pupperlimloss，pupperlimloss）。我们最近的VA资助（RX 001388，RX 001322）研究 已经提出，患有痉挛的人经历高患病率的福尔斯并表现出姿势控制 可能损害稳定性的机制。具体来说，近一半的人与腕关节或近端 一级的人每年至少经历一次跌倒，几乎三分之一的人会经历两次或两次以上的福尔斯。此外，使用A 假肢使跌倒的可能性增加了6倍，25%的报告福尔斯跌倒是由于绊倒， 三分之一经历跌倒的人遭受与跌倒有关的伤害。福尔斯可以有相当大的经济 对VHA造成负担，并导致长期生活质量下降。我们的生物力学研究表明， 与身体健全的人相比，单侧痉挛的人在站立时表现出更大的姿势摇摆， 戴假肢时增加，运动稳定动力学中的右/左不对称性可能[增加] 向受损肢体侧和健全肢体侧跨步期间跌倒的风险]。这些发现强调 需要进行更多的研究，以更好地了解退伍军人控制平衡的机制 以及如何[戴上]假肢[影响]这些策略。因为我们之前的研究关注的是稳定的- 状态表征的姿势控制，我们现在计划建立在这项工作的影响， [佩戴]假肢对行走过程中对绊倒干扰做出反应时的运动稳定性。在这一背景下， 运动稳定性被定义为从扰动中恢复并回到稳态步态的能力。 我们将通过分析旅行引起的主动和反应性运动策略的差异来解决研究目的 在两项研究比较中：1）单侧经桡动脉水平骨折的退伍军人与匹配的健全对照组 [（有和没有一个手臂束缚）]，和2）退伍军人与单侧经桡动脉狭窄时，穿着他们的习惯 不戴假肢的人。控制，但意想不到的，模拟旅行将交付 通过我们定制的跑步机，允许可编程的皮带速度干扰，并允许参与者 恢复后继续行走。我们将描述主动和被动运动[稳定性 机制]通过一组生物力学（时空，角动量，手臂和躯干运动学， 恢复步长和时间）和肌电图（上肢和下肢肌肉激活时间和努力） 变量生物力学变量将使用光学运动捕捉系统进行量化， 将用无线传感器系统收集肌电图。所有数据将相互同步 以及表示踏车扰动开始的时间脉冲。我们希望有残疾的退伍军人 与对照组相比，证明[改变的]运动稳定性[机制]，[这些差异将存在 戴与不戴之间的区别。这项研究的结果将有助于我们描述 运动稳定性的潜在机制，并确定与之相关的因素， 与旅行相关的福尔斯患病率增加。这些知识是解决这一公众问题的关键第一步 通过旨在减少福尔斯跌倒、跌倒相关伤害 和相关的VHA成本。我们将利用这项试点研究的结果， 未来VA优异奖提案[开发和]评估[体能训练]干预方法和[可穿戴 和假肢技术，以提高稳定性的退伍军人与脊髓灰质炎]。VHA是追求这一目标的理想场所 作为其主要优先事项之一的工作是提高护理标准的退伍军人与肢体损失。

The primary aim of this pilot study is to characterize the proactive and reactive locomotor response of Veterans with upper limb loss (ULL) to a trip during walking. Our recent VA-funded (RX001388, RX001322) investigations have suggested that persons with ULL experience a high prevalence of falls and demonstrate postural control mechanisms that may impair stability. Specifically, nearly half of individuals with ULL at or proximal to the wrist level experience at least one fall per year and almost a third will experience two or more falls. Further, use of a prosthesis increases the likelihood of falling by six times, 25% of reported falls resulted from tripping, and nearly a third of individuals who experience a fall suffer a fall-related injury. Falls can have considerable economic burden on the VHA and lead to long-term diminished quality of life. Our biomechanical studies suggest that persons with unilateral ULL display greater postural sway during standing than able-bodied individuals which increases when wearing a prosthesis, and right/left asymmetry in locomotor stability dynamics that may [increase the risk of falling toward the impaired limb side and during sound limb side strides]. These findings emphasize the need for additional research to better understand the mechanisms Veterans with ULL use to control balance and how [wearing a] prosthesis [affects] these strategies. As our previous research was concerned with steady- state characterization of postural control, we now plan to build on this work by studying the effects of ULL and [wearing a] prosthesis on locomotor stability when responding to a trip disturbance during walking. In this context, locomotor stability is defined as the ability to recover from a perturbation and return to steady-state gait. We will address the study aims by analyzing trip-induced proactive and reactive locomotor strategy differences in two study comparisons: 1) Veterans with unilateral transradial level ULL against matched able-bodied controls [(with and without one arm bound)], and 2) Veterans with unilateral transradial ULL when wearing their customary prosthesis against not wearing their prosthesis. Controlled, yet unexpected, simulated trips will be delivered through our custom-built treadmill which permits programmable belt velocity disturbances and allows participants to continue walking following recovery. We will characterize the proactive and reactive locomotor [stability mechanisms] through a set of biomechanical (spatiotemporal, angular momentum, arm and trunk kinematics, recovery step length and time) and electromyography (upper and lower limb muscle activation timing and effort) variables. Biomechanical variables will be quantified using an optical motion capture system, and electromyography will be collected with a wireless sensor system. All data will be synchronized with each other and a time pulse denoting the onset of the treadmill perturbation. We expect that Veterans with ULL will demonstrate [altered] locomotor stability [mechanisms] compared to controls, and [these differences will exist between wearing and not wearing] their customary prosthesis. Results from this study will help us characterize the underlying mechanisms of locomotor stability in Veterans with ULL and identify the factors associated with their increased prevalence of trip-related falls. Such knowledge is a critical first step to addressing this public health problem through stability-targeted rehabilitation interventions aimed at reducing falls, fall-related injuries, and associated VHA costs in this Veteran patient group. We will use the outcomes from this pilot study to guide future VA Merit Award proposals to [develop and] assess [physical training] intervention methods and [wearable and prosthetic technology to improve stability in Veterans with ULL]. The VHA is an ideal venue to pursue this work as one of its main priorities is to elevate the standard-of-care for Veterans with limb loss.