Contributions of lower extremity musculature to hip and knee joint coordination, stability, and regional tissue mechanics

该计划的长期目标是开发一个工程工具和计算模型的研究平台，以建立从组织到整个关节水平的关节力学的全面了解。这项工作的总体愿景是，它将产生有效的信息，以改进减少腿部损伤、治疗和康复战略，从而降低医疗保健成本，提高患者满意度，并使加拿大普通人口更舒适地老龄化。这将通过以下目标来解决：目标1)量化个体肌肉对膝关节和髋关节稳定性的贡献，以响应多平面和多关节任务。这一目标的目的是确定下肢肌肉对髋关节和膝关节运动学和动力学的贡献。这项研究将表明每一块腿部肌肉在启动不同类型的运动和稳定关节方面的作用。目的2)量化主动和被动加载方案下膝关节和髋关节软组织结构的局部应力应变分布。在我的实验室开发的定制设计的与Micro-CT兼容的关节运动模拟器将被改造，以便它能够对身体标本施加主动肌肉力量。使用基于CT成像的方法，可以计算区域韧带材料的属性。本研究目标的结果将描述肌肉贡献对髋关节和膝关节韧带应力和应变的影响。目的3建立关节接触力学有限元模型并进行验证。基于图像的有限元模型将通过目标2中的CT扫描来开发和验证。肌腱将被建模为二维纤维增强膜和非线性弹簧单元，而韧带将被建模为非线性弹簧。在验证后，将量化关节内的接触机制，并在不同的加载条件下进行比较。来自目标1的肌腱作用力将被输入到模型中以模拟主动肌肉负荷。我预计这项工作的完成将导致迄今为止最全面的局部组织力学特性图，以及这些特性如何受到不同类型的生理负荷和周围肌肉系统的影响。

The long-term goal of this program is to develop a research platform of engineering tools and computational models of the lower extremity to build a comprehensive understanding of joint mechanics ranging from the tissue to whole joint levels. The overall vision of this work is that it will produce valid information to improve lower extremity injury reduction, treatment and rehabilitation strategies resulting in reduced health care costs, improved patient satisfaction and more comfortable ageing of the general Canadian population. This will be addressed through the following objectives: Objective 1) Quantify the individual muscle contributions to knee and hip joint stability in response to multi-planar and multi-joint tasks. The purpose this objective is to determine the contributions of the lower extremity musculature to hip and knee joint kinematics and kinetics. This research will indicate the role of each of the lower extremity muscles in initiating different types of motion and stabilizing the joints. Objective 2) Quantify regional stress and strain distributions in knee and hip joint soft tissue structures in response to active and passive loading protocols. A custom designed micro-CT compatible joint motion simulator, developed in my lab, will be adapted so that it is capable of applying active muscle forces to cadaveric specimens. Using a CT imaging based method, regional ligament material properties can be calculated. The results of this research objective will describe the effect of muscle contributions on hip and knee joint ligament stresses and strains. Objective 3 Development and validation of finite element models to measure joint contact mechanics. Image based finite element models will be developed and validated from CT scans taken in objective 2. Muscle tendons will be modelled as two-dimensional fiber reinforced membranes and non-linear spring elements while the ligaments will be modelled as non-linear springs. Following validation the contact mechanics within the joints will be quantified and compared across different loading conditions. The muscle-tendon forces from objective 1 will be input into the models to simulate active muscle loading I anticipate that the completion of this work will result in the most comprehensive mapping of regional tissue mechanical properties to date and how these are affected by different types of physiological loading and the surrounding musculature.