Improving Dynamic Walking Stability in Traumatic Amputees

描述（申请人提供）：步行是一项极其重要和常见的日常活动。许多运动障碍增加了人们摔倒的风险。到2020年，所有与跌倒有关的伤害的总成本可能达到438亿美元。每年有多达60%的下肢截肢患者摔倒。对于创伤性截肢的年轻患者来说，跌倒尤其成问题，他们比老年患者摔倒的次数略多。大多数人走路时摔倒了。此外，指导干预措施设计以改善截肢患者行走功能的科学证据也非常有限。因此，有必要更好地了解下肢截肢患者对生态相关干扰的反应，确定这些患者在受到干扰后用于恢复平衡的生物力学和神经肌肉策略，并制定有效的基于证据的治疗策略来帮助这些患者提高行走稳定性。我们的实验室已经开发出新的工程方法来测量行走稳定性，直接量化人类对小扰动的反应。这项研究的主要目标是开发干预措施，以帮助预防跌倒。这需要在下跌发生之前进行干预。虽然跌倒本身是非常难以捉摸的事件，但重大绊倒是非常常见的。在老年人中，绊倒或绊倒导致一半以上的跌倒。因此，绊倒是跌倒的主要前兆之一。绊倒常常导致害怕摔倒，过度小心，减少体力活动。然而，令人惊讶的是，没有研究量化下肢截肢患者的绊脚石反应。在这个项目中，我们将首先确定胫骨截肢患者对小的、连续的伪随机视觉或机械扰动的反应，类似于他们在不平坦的地形上或在拥挤的公共场所行走时可能遇到的情况。我们还将直接测试常见的临床假设，即这些患者由于远端体感反馈的丧失而更加依赖视力。其次，我们将确定经胫骨截肢患者在行走过程中对大的离散机械扰动的反应，例如他们在路边绊倒或踩到一个坑洞时可能遇到的情况。从这些数据中，我们将确定截肢者在跌倒后用来恢复平衡的特定生物力学和神经肌肉策略。最后，我们将确定基于虚拟现实的定向步态训练是否比传统疗法更成功地改善胫骨截肢患者的行走稳定性。一个完全沉浸式的虚拟环境将允许我们应用高度控制和生态相关的扰动，我们预计这将更容易推广到现实世界的行走中。本研究将采用新颖的实验和严谨的分析方法，以显著提高我们对截肢患者对扰动的反应的理解。我们将根据我们的科学发现开发康复干预措施，将这些知识转化为临床实践。最后，这项工作将为制定更好的干预措施以改善其他步行相关障碍人群的步行功能提供科学依据。

DESCRIPTION (provided by applicant): Walking is an extremely important and common daily activity. Many locomotor impairments increase people's risk of falling. The total costs of all fall-related injuries may reach $43.8 billion by 2020. As many as 60% of patients with lower extremity amputation fall each year. Falls are especially problematic for young patients with traumatic amputation, who fall slightly more than older patients. Most people fall while they are walking. Also, very limited scientific evidence exists to guide design of interventions to improve walking function in patients with amputation. Thus, there is a clear need to better understand how patients with lower limb amputation respond to ecologically relevant perturbations, to identify the biomechanical and neuromuscular strategies these patients use to recover balance after being perturbed, and to develop effective evidence based treatment strategies to help these patients improve their walking stability. Our lab has developed novel engineering approaches to measure walking stability that directly quantify how humans respond to small perturbations. The primary goal of this study is to develop interventions to help prevent falls. This requires intervening before the fall itself occurs. While falls themselves are very elusive events, significant stumbles are very common. In the elderly, stumbling or tripping causes more than half of all falls. Therefore, stumbling is one of the primary precursors to falling. Stumbles often lead to fear of falling, excessive caution, and decreased physical activity. Surprisingly, however, no study has quantified stumbling responses in patients with lower limb amputation. For this project, we will first determine how patients with trans-tibial amputation respond to small, continuous pseudo-random visual or mechanical perturbations, similar to those they might experience walking outdoors over uneven terrain or in crowded public places. We will also directly test the common clinical assumption that these patients rely more heavily on vision because of their loss of distal somatosensory feedback. Second, we will determine how patients with trans-tibial amputation respond to large discrete mechanical perturbations during walking, such as they might experience when tripping over a curb or stepping in a pothole. From these data, we will identify specific biomechanical and neuromuscular strategies amputees use to recover balance after they stumble. Finally, we will determine if targeted virtual reality based gait training is more successful than conventional therapy for improving walking stability in patients with trans-tibial amputation. A fully immersive virtual environment will allow us to apply highly controlled and ecologically relevant perturbations, which we anticipate will generalize more readily to real world walking. This study will apply novel experimental and rigorous analytical approaches to significantly improve our understanding of how patients with amputation respond to perturbations. We will translate this knowledge into clinical practice by developing rehabilitation interventions based on our scientific findings. Finally, this work will provide a scientific basis for developing better interventions to improve walking function in populations with other walking related impairments. PUBLIC HEALTH RELEVANCE: Falls and the injuries that result from falls are a significant health care problem for the thousands of patients who undergo lower limb amputation every year, as well as for millions of elderly and patients with other locomotor impairments. Determining how these patients use their available sensory and motor resources to regulate stability during walking and developing effective evidence based treatment strategies to improve their walking stability will significantly extend and improve the lives of these patients. The proposed work will apply novel state-of-the-art experimental and analytical approaches to directly address these critical issues.