Development and validation of a musculoskeletal model of the pelvis in response to lateral impacts

我的一般兴趣领域是与组织负荷相关的肌肉骨骼生物力学，以及老年在这些关系中的作用。在此框架内，本研究计划将对骨盆侧向碰撞动力学的基本机制产生新的见解。在拟议拨款的5年期限内，我的短期目标是表征髋部侧落时撞击开始时身体的系统状态参数（主题1）。这些知识将为开发和验证一个强大的数学模型的中期目标提供信息，该模型可以准确地预测在跌倒相关撞击期间施加在骨盆上的载荷。模型开发的初始阶段将侧重于人类志愿者的低能量影响（主题2）。具体来说，200名参与者将以不同的身体形态在臀部进行低能量侧身摔倒。收集的数据将包括施加力、压力分布、运动学和肌肉激活水平。此外，详细的骨骼几何形状和身体成分评估将使用双x线吸收仪、超声波和身体阻抗分析进行。由此产生的数据将用于开发一个数学模型，该模型可以准确预测在髋部侧身摔倒时施加在侧骨盆上的时变载荷。将评估各种模型类型，包括：i)集总参数；赫兹接触；iii)多元回归方法。最有希望的模型将使用参与者数据的子集进行初始验证。在主题3中，尸体（通过滑铁卢大学解剖学院访问）将用于进一步验证或完善骨盆撞击模型。除了复制人类志愿者进行的低严重程度的撞击外，模型验证将扩展到更能代表最坏情况的坠落场景的更高能量的撞击。研究的主题4将采用类似的方法，但将利用机械髋关节撞击模拟器（即跌落塔）来生成用于后续模型验证/改进的实验数据。拟议研究的最后阶段（主题5）将利用所有实验范式来研究新型工程设备和材料在髋关节侧落过程中改变冲击动力学的能力。综上所述，本文提出的研究是新颖的，它使用了互补的研究范式，这些范式将共同产生一个强大的、非常有效的骨盆侧碰撞肌肉骨骼模型。此外，所得到的数据将为基于工程的保护装置和材料的生物力学特性提供基本见解，这些特性可以在未来的研究应用中集成到更有效产品的设计中。

My general field of interest is musculoskeletal biomechanics related to tissue loading, and the role that advanced age has on these relationships. Within this framework, the proposed program of research will generate novel insights into the basic mechanisms underlying dynamics of the pelvis during lateral impacts. For the 5-year horizon of the proposed grant, my short-term objectives are to characterize system state parameters of the body at the moment of impact initiation during lateral falls on the hip (Theme 1). This knowledge will inform the medium-term objectives of developing and validating a robust mathematical model that accurately predicts the loads applied to the pelvis during fall-related impacts. The initial stages of model development will focus on low-energy impacts from human volunteers (Theme 2). Specifically, 200 human participants will undergo low-energy sideways falls on the hip in a variety of body configurations. Data collected will include applied forces, pressure distribution, kinematics, and muscle activation levels. In addition, detailed skeletal geometry and body composition assessments will be conducted using dual x-ray absorptiometry, ultrasound, and body impedance analysis. The resulting data will be used to develop a mathematical model that accurately predicts the time-varying loads applied to the lateral pelvis during sideways falls on the hip. A variety of model types will be evaluated including: i) lumped-parameter; ii) Hertzian contact; and iii) multiple regression approaches. The most promising model will undergo initial validation using a subset of participant data. In Theme 3, cadavers (accessed through the University of Waterloo’s School of Anatomy) will be used to further validate, or refine, the pelvic model of impact. In addition to replicating the low severity impacts performed by human volunteers, model validation will be extended to higher energy impacts more representative of worst-case fall scenarios. Theme 4 of the research will employ similar approaches, but will utilize mechanical hip impact simulators (i.e. a drop tower) to generate the experimental data used for subsequent model validation/refinement. The final phase of the proposed research (Theme 5) will utilize all experimental paradigms to investigate the ability of novel engineering devices and materials to alter impact dynamics during lateral falls on the hip. In summary, the proposed research is novel in its use of complementary research paradigms that will collectively result in a robust, and extremely well-validated, musculoskeletal model of the pelvis in response to lateral impacts. In addition, the resulting data will provide fundamental insights into the biomechanical properties of engineering-based protective devices and materials which could be integrated into the design of more effective products in future research applications.