人体肌骨的多柔体系统动力学研究进展

人体肌肉骨骼系统简称肌骨系统, 包括骨骼、骨骼肌与关节连接, 其力学模型是典型的多柔体系统. 从多体动力学角度研究肌骨系统, 主要关注其在运动过程中的肌肉内力、关节力矩及产生的动力学影响, 属于动力学与生物力学的交叉融合. 肌骨系统的多体动力学模型已被广泛地应用于临床医学、竞技体育、军事训练、人机工程等诸多领域, 其仿真结果可为提高人体运动能力、降低关节载荷与能耗、避免运动损伤、加快康复进程等提供重要计算参考数据. 与此同时, 上述研究亦对肌骨动力学研究提出了许多新挑战. 本文综述了人体肌骨多柔体系统动力学相关研究进展, 包括骨骼肌功能解剖与生物力学建模、神经与肌肉控制理论、肌骨系统动力学问题与求解方法, 以及近年来肌骨多体动力学在步态分析、飞行员抗荷动作、口颌手术规划等领域的典型应用. 与工程领域的机械多体系统相比, 人体肌骨多体系统具有肌肉内力主动性与肌肉控制冗余性两大特征. 现有骨骼肌模型难以同时考虑肌肉的解剖结构、三维几何与肌力产生的生物化学机制. 已有大多数肌骨模型采用静态优化假设消除肌肉冗余性, 忽略了肌肉与肌腱内力平衡及兴奋收缩耦联机制. 此外, 目前仍缺乏实现肌骨模型个性化的无创在体测试手段. 未来, 人体肌骨多体动力学研究将会向更精确、智能、个性化的方向发展, 成为动力学与生物力学交叉的热点研究领域. 

Advances in flexible multibody dynamics of human musculoskeletal systems

The human system consists of bones, skeletal muscles, and joints, so the system model in mechanics is a typical flexible multi-body system. The study on musculoskeletal multi-body dynamics mainly aims to determine muscle forces and joint moments together with the effect of their actions during human locomotion. Thus, it is a multi-disciplinary subject between dynamics and biomechanics. Musculoskeletal multi-body models have seen successful applications in many fields, such as clinical research, sports engineering, military training, and ergonomics. The simulation results of these models can provide important data for improving physical performances, reducing joint loading and energy consumption, preventing sports injuries, and accelerating rehabilitation processes. In turn, the achievement of these human-related techniques provides the study of musculoskeletal dynamics with numerous new challenges. This review surveys the literature on the multi-body dynamics modeling of human musculoskeletal systems. Its contents include the functional anatomy and biomechanical models of the skeletal muscle, neuromuscular control strategies, and the computational frameworks for musculoskeletal modeling. The paper also reviews several typical applications of musculoskeletal modeling in the fields of gait analysis, anti-G straining maneuver of pilots, and mandibular surgical planning. Compared with classical mechanical systems in mechanical engineering, the human musculoskeletal system has the characteristics of active force and redundancy control. However, existing muscle models cannot simultaneously consider the anatomical structures and three-dimensional geometries of the muscles together with their biochemical force-generating mechanism. Meanwhile, most studies have utilized the static optimization assumption to deal with muscle recruitments, neglecting the equilibrium between musculotendon forces and contraction dynamics. So far, It is still a challenging task to build subject-specific musculoskeletal models based on non-invasive in vivo measurements. Future studies on musculoskeletal multi-body dynamics will achieve a more precise, intelligent, and subject-specific modeling framework, which leads to a hot research topic involving interdisciplinary collaborations of dynamics and biomechanics.