Development of Mechanical Testing Systems to Perform Comprehensive Biomechanical Assessments of the Shoulder

与过去三十年来为髋关节、膝关节和脊柱开发的众多生物力学测试方法不同，肩部测试系统相对较少且处于起步阶段。实验肩部装置通常采用静态加载协议对尸体标本进行等距（即静止）测试。最近的一些系统使用简化的肌肉控制协议和/或机器人技术产生手臂运动。然而，这些方法不能完全重现整个关节的肌肉负荷或达到足够的速度控制。此外，常见的举臂动作包括旋转球窝关节（盂肱关节）和肩胛骨到躯干关节（肩胛骨胸椎关节）。这两种运动在实验环境中还没有得到很好的证实。合理的假设是，优化我们对这种联合的理解和评估需要开发和应用先进的综合测试方法。因此，这项发现提案将侧重于开发和应用新的肩部测试系统和测量技术，用于肩部的实验生物力学研究。这些进展是对该关节生物力学更全面理解的重要先导。此外，植入物的发育和重建在很大程度上依赖于广泛的生物力学测试和分析。新的“反向”假体尤其如此，这种假体的头部和关节窝是反向的，以便在手臂抬高时提供机械优势。虽然这些材料越来越受欢迎，但需要更好的测试方法来更全面地了解它们的机械性能。这项研究的长期目标是阐明肩关节的生物力学，并为其评估提供一个可靠而全面的方法。本建议的短期总体目标是开发和采用先进的肩部测试系统和分析技术来研究肩部外展（手臂抬高）运动的生物力学，特别对植入物测试感兴趣。两个具体目标是：1)使用一个能够同时进行肩胛和肩胛骨运动的体外测试模拟器来理解肩关节的生物力学。2)通过特殊设计的器械植入系统，确定肩关节植入物的设计和定位对关节负荷的影响。本文提出的工作将导致对肩部生物力学理解的新发现。这些发展也将导致最先进的测试项目的发展，这将允许对肩膀进行广泛的先进研究。此外，提出的详细调查将产生重要的结果和发现，这将有助于改进我的小组和其他人的测试方法和计算模型。最终，这个五年计划的完成将很有可能确保我们的实验室将继续在这一性质的研究中脱颖而出，并在肩部生物力学评估方面处于世界领先地位，在实验测试和建模的综合方法方面具有特殊的专业知识。

Unlike the multitude of biomechanical testing approaches that have been developed for the hip, knee, and spine over the past three decades, shoulder testing systems are relatively few and in their infancy. Experimental shoulder devices typically employ static loading protocols on cadaver specimens to produce isometric (i.e. stationary) testing. Some recent systems have produced arm motion using simplified muscle controlling protocols and/or robotics. However, these approaches do not fully reproduce muscle loading across the joint or achieve adequate velocity control. Moreover, common maneuvers such as arm elevation involve rotation of both the ball and socket (glenohumeral) joint, and the shoulder blade to trunk (scapulothoracic) articulation. These two motions have not been well established in the experimental setting. It is logical to postulate that optimizing our understanding and evaluation of this joint necessitates the development and application of advanced comprehensive testing approaches. Hence, this discovery proposal will focus on the development and application of novel shoulder-testing systems and measurement techniques for experimental biomechanical investigations of the shoulder. These developments are an important precursor to a more complete understanding of the biomechanics of this joint. Further, implant development and reconstruction relies heavily on extensive biomechanical testing and analyses. This is especially true of new “reverse” prosthesis where the head and socket are reversed to provide a mechanical advantage during arm elevation. While these are rapidly growing in popularity, better testing approaches are needed to more fully comprehend their mechanical performance. The long-term objective of this research is to elucidate the biomechanics of the shoulder and provide a robust and comprehensive approach to its evaluation. The short-term overall objective of this proposal is to develop and employ advanced shoulder-testing systems and analysis techniques to investigate the biomechanics of the shoulder for abduction (arm elevation) motion, with special interest in implant testing. The two specific objectives are: 1) To comprehend the biomechanics of the shoulder using an in-vitro testing simulator capable of both glenohumeral and scapulothoracic motion. 2) To establish how shoulder implant design and positioning affects joint loading using a specially designed instrumented implant system. The work proposed herein will lead to new discoveries related to the understanding of the biomechanics of the shoulder. These developments will also result in the evolution of a state of the art testing program that will permit a wide range of advanced research-based studies on the shoulder. Furthermore, the detailed investigations proposed will yield important results and findings that will contribute to improving testing approaches and computational models by my group and others. Ultimately, completion of this 5-year plan will very likely ensure that our laboratory will continue to excel in research of this nature, and be a world leader for the biomechanical assessment of the shoulder, with special expertise in comprehensive approaches to experimental testing and modelling.