How biomechanical factors and compensatory strategies influence joint contact forces?

许多研究报告说，个人特征（例如，年龄、性别、遗传因素）和生物力学因素的差异（例如，体重、机械排列）可能使关节易患退行性疾病。研究还报告说，一些补偿战略（例如，增加脚趾外伸角度、增加躯干倾斜度）通常被个体在日常活动中（有意识或无意识地）采用以科普关节紊乱，从而使疼痛最小化。为了量化这些策略的有效性，作者通常报告了步态期间下关节力矩的减少。然而，最近的研究质疑这些参数对关节接触力最小化的真实的影响。根据我们的知识，关于代偿策略的影响以及它们与生物力学因素对关节完整性的相互作用（即，关节完整性的保持可以表示为关节接触表面上载荷的最佳分布的结果）在功能任务期间（例如，楼梯上升和下降，坐到站过渡）。 拟议的研究计划的长期目标是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，在动态评估的背景下。 具体目标是（1）确定生物力学因素对功能任务期间下关节力矩大小的影响（即，水平步态、从坐到站、上楼梯和下楼梯）;（2）确定在功能任务期间补偿策略对最小化下关节力矩的贡献（即，水平步态、坐立、上下楼梯）;（3）使用肌肉骨骼模型来量化补偿策略对降低关节力矩和最小化下肢关节接触力的贡献;（4）使用复杂的统计方法来更好地理解生物力学因素和补偿策略之间的相互作用，以控制功能任务期间的关节接触力。 这项研究计划将有助于理解生物力学因素和补偿策略，这些因素和策略对功能任务期间关节接触力的减少有重大贡献。更具体地说，它将有助于增加我们对生物力学因素、全身机制和对机械关节完整性具有显著影响的人类内在特征之间的相互作用及其对与各种关节相关的机械生物学特性退化的可能未来贡献的知识（例如，膝盖，臀部）。最后，拟议的计划将增加与个人使用的补偿策略，以减少联合负荷的知识。

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.