How biomechanical factors and compensatory strategies influence joint contact forces?

许多研究报道，个体特征(如年龄、性别、遗传因素)和生物力学因素(如体重、机械排列)的差异可能使关节易患退行性疾病。研究还报告说，在日常活动中(有意识或无意识地)，个人经常采用一些补偿策略(例如，增加脚趾外露角度，增加躯干倾斜)来应对关节紊乱，以将疼痛降至最低。为了量化这些策略的效率，作者通常报告了步态中下关节力矩的减少。然而，最近的研究质疑这些参数对最小化关节接触力的真正影响。根据我们的知识，在功能性任务(如楼梯上升和下降)过程中，补偿策略以及它们与生物力学因素对关节完整性的影响(即，关节完整性的保持可以表示为关节接触面上载荷的最佳分布)的影响知之甚少。*拟议研究计划的长期目标是在动态评估的背景下更好地了解生物力学因素和补偿策略对下半身关节完整性的影响。*具体目标是(1)确定生物力学因素对功能任务(即水平步态、坐立、楼梯上升和下降)下关节力矩大小的贡献；(2)确定补偿策略在功能任务(即水平步态、坐立、楼梯上升和下降)中对最小化下关节力矩的贡献：(3)使用肌肉骨骼模型来量化补偿策略对减少关节力矩和最小化下肢关节接触力的贡献；(4)使用复杂的统计学方法，更好地了解生物力学因素与补偿策略之间的相互作用对控制功能任务中关节接触力的作用。*本研究计划将有助于理解在功能任务中对减少关节接触力有重要贡献的生物力学因素和补偿策略。更具体地说，它将有助于增加我们对生物力学因素、全身机制和人类固有特征之间的相互作用的了解，这些因素对机械关节的完整性具有重要影响，以及它们未来可能对与各种关节(如膝盖、髋关节)相关的力学-生物学特性的退化做出贡献。最后，拟议的计划将增加与个人使用的补偿策略相关的知识，以减少联合负荷。

Many studies have reported that individual characteristics (e.g., age, sex, genetic factors) and differences in biomechanical factors (e.g., body weight, mechanical alignment) may predispose the joint to degenerative diseases. Studies also report that some compensatory strategies (e.g., increased toe-out angle, increase trunk lean) are often adopted by individuals during daily activities (consciously or not) to cope with joint disorders in order to minimize pain. To quantify the efficiency of these strategies, authors generally reported the reduction of lower joint moments during gait. However, recent studies have questioned the real impact of these parameters on the minimization of joint contact forces. Based on our knowledge, little is known about the influence of compensatory strategies as well as their interaction with biomechanical factors on joint integrity (i.e., the preservation of joint integrity could be represented as the result of optimal distribution of loads on joint contact surfaces) during functional tasks (e.g., stair ascent and descent, sit-to-stand transition).******The long term goal of the proposed research program is to better understand both the influence of biomechanical factors and compensatory strategies on lower body joint integrity in a dynamic context of evaluation.***The specific objectives will be (1) to determine the contribution of biomechanical factors on the magnitude of lower joint moments during functional tasks (i.e., level gait, sit-to-stand, stair ascent and descent); (2) to determine the contribution of compensatory strategies on the minimization of lower joint moments during functional tasks (i.e., level gait, sit-to-stand, stair ascent and descent); (3) to use a musculoskeletal model to quantify the contribution of compensatory strategies to the reduction of joint moments and minimization of joint contact forces at the lower limb and; (4) to use a complex statistical approach to better understand the interactions between biomechanical factors and compensatory strategies on the control of joint contact forces during functional tasks.******This research program will contribute significantly to the understanding of biomechanical factors and compensatory strategies that have a major contribution on the reduction of joint contact forces during functional tasks. More specifically, it will contribute to increase our knowledge about the interactions between biomechanical factors, whole-body mechanisms and human intrinsic characteristics having significant impact on mechanical joint integrity and their possible future contribution to the degeneration of mechanical-biological properties associated with the various joints (e.g., knee, hip). Finally, the proposed program will add knowledge related to compensatory strategies used by individuals to reduce joint loads.