Posture and control based mechanisms of upper extremity disorders

在过去的几十年里，在理解人类运动以及残疾如何阻碍正常功能方面取得了巨大进展。非常需要充分了解人类上肢（肩、臂和手）在日常使用中受伤的机制。这些疾病涉及肌肉组织（肌肉疼痛）、结缔组织（例如网球肘）和周围神经（例如腕管综合征）。通过了解运动的控制以及肌肉、肌腱和韧带力量在手臂内部相互作用的方式，我们最终可以预防疾病，特别是那些在工作中发展的疾病。 与下背部损伤不同，上肢疾病往往随着时间的推移而发生，不能归因于特定事件，因此上肢损伤的机械起源是难以捉摸的。研究表明，负荷、姿势和运动与受伤风险高度相关。控制手部、手臂和肩部肌肉的补偿策略可能表明哪些个体容易受到更大的个体肌肉负荷、疲劳和损伤的影响。我的研究计划通过监测手臂运动，肌肉活动及其与基于计算机的建模的相互作用，有条不紊地调查肌肉负荷的影响。我们使用磁共振成像（MRI）和超声检查在不同的手腕姿势捏动作，以确定力学的神经压迫腕管综合征的手腕结构变化。我们还研究了肩部、手臂和手部肌肉的激活模式（时间和幅度），以确定肌肉如何在特定任务中产生运动。通过这些研究，当人们的肌肉是新鲜的，当他们疲劳时，我们可以确定人们是如何处理令人疲劳的刻板动作的，比如在装配线上。这项研究计划的一个主要部分是开发和改进计算机模型，以预测手臂和手部的力量。通过在计算机模型中结合肌肉活动和解剖数据，我们可以测试有关疾病如何发展以及如何预防疾病的理论，并提出“如果......会发生什么？“这些问题在道德上是无法回答的。

Over the past few decades, great advances have been made in the understanding human movement and how disabilities impede normal function. There is a great need to fully understand the mechanisms by which the human upper extremity (shoulder, arm, and hand) becomes injured with everyday use. These disorders involve muscle tissue (muscle pain), connective tissue (e.g. tennis elbow), and peripheral nerves (e.g. carpal tunnel syndrome). By understanding the control of movement and the way muscle, tendon and ligament forces interact inside the arm, we can ultimately prevent disorders, especially those developed at work. Unlike injuries to the lower back, disorders of the upper extremity tend to occur over time and cannot be attributed to a specific event, thus the mechanical origins of upper extremity injuries are elusive. Studies indicate that loads, postures and motion are highly linked to injury risk. Compensatory strategies to control the hand, arm and shoulder muscles may indicate which individuals are susceptible to greater individual muscle loading, fatigue and injury. My research program methodically investigates the effects of muscular loading by monitoring arm movement, muscle activity and their interactions with computer-based modeling. We use magnetic resonance imaging (MRI) and ultrasound to examine structural changes in the wrist in different wrist postures during pinching actions to determine mechanics of nerve compression in carpal tunnel syndrome. We also examine the activation patterns (timing and magnitude) of shoulder, arm and hand muscles to determine how muscles work to create movement in specific tasks. By doing studies such as these when people's muscles are fresh and when they are fatigued, we can determine the way people deal with tiring stereotypical movements like on an assembly line. A major part of this research program is to develop and improve the computer model to predict forces inside the arm and hand. By combining muscle activity and anatomical data in a computer model, we can test theories on how disorders develop and how to prevent them as well as ask "what would happen if ...?" questions that otherwise could not be answered ethically.