MUSCULOSKELETAL STIFFNESS AND LOCOMOTION

肌肉、肌腱和韧带具有弹簧般的特征。因为 当关节弯曲或伸展时，这些肌肉骨骼元素会改变长度， 关节表现出弹簧般的特征也就不足为奇了。这个 肌肉骨骼僵硬的控制是复杂的，影响因素很多。 影响每个关节的刚度。然而，在一些多关节的情况下 动作，包括哺乳动物的奔跑，动作的元素 肌肉骨骼系统集成在一起，使整体 肌肉骨骼系统表现出弹簧般的行为。实验 关于跑步步态的机制的研究结果显示，总体来说 肌肉骨骼系统的行为就像一个线性弹簧 到目前为止，研究的哺乳动物包括奔跑的人类，小跑的狗和 马和跳跃的袋鼠。这一观察结果导致了 用于跑步的弹簧-质量模型，由单个线性无质量 “腿弹簧”和一个质量块。“腿弹簧”指的是像弹簧一样的 人体整体肌肉骨骼系统的特点 运动，质量等于动物的质量。这个 拟议研究的总体目标是了解 肌肉骨骼僵硬和运动生物力学之间的联系。 考虑到控制单个肌肉或肌肉僵硬的复杂性 关节，使用前向动力学方法开始是不现实的 在单个肌肉的僵硬水平上，并试图解释 跑步的技巧。我们建议使用逆动力学方法 首先，我们将重点放在运动力学和 整体肌肉骨骼僵硬。在特定目标1的保护伞下， 调整整体刚性的重要性 肌肉骨骼系统以适应在不同地形上跑步 检查过了。这项研究将涉及检查对 在不同硬度表面上跑步时的肌肉骨骼硬度 以及可预测性各不相同的表面。在特定目标的保护伞下 2、我们将进行一系列相关的研究，以检验这些机制 用于调整整个肌肉骨骼系统的僵硬程度 跑步。这些研究将包括检查 在运动过程中，腿部单个关节的刚度可以调整。 此外，它还将涉及审查变化的相对重要性 要把关节的刚度和姿势放在调整整体刚度上 跑步时的肌肉骨骼系统。在这两种特定条件下的实验 目标L和2将涉及运动学和运动学相结合的分析 跑步以确定整体肌肉骨骼僵硬和关节 僵硬。这些发现将为最优设计提供新的信息 地板和轨道，以最大限度地减少过度使用期间的伤害 负重有氧运动与弹簧基础的优化设计 假肢和机械腿。最后，我们的研究将开始 将关节刚度的神经控制知识应用于 理解由所有人执行的自然活动的机制 有腿的动物，运动。

Muscles, tendons, and ligaments have spring-like characteristics. Because these musculoskeletal elements change length when joints flex or extend, it is not surprising that joints exhibit spring-like characteristics. The control of musculoskeletal stiffness is complex with many factors affecting the stiffness of each joint. However, in some multi-jointed movements, including mammalian running, the elements of the musculoskeletal system are integrated together so that the overall musculoskeletal system exhibits spring-like behavior. Experimental findings on the mechanics of running gaits have revealed that the overall musculoskeletal system behaves like a single linear spring in all of the mammals studied to date, including running humans, trotting dogs and horses, and hopping kangaroos. This observation has led to the development of a spring-mass model for running, consisting of a single linear massless "leg spring" and a mass. The "leg spring" represents the spring-like characteristics of the overall integrated musculoskeletal system during locomotion, and the mass is equivalent to the mass of the animal. The general objective of the proposed research is to gain an understanding of the link between musculoskeletal stiffness and locomotion biomechanics. Given the complexity of the control of the stiffness of a single muscle or joint, it is not realistic to use a forward dynamics approach that begins at the level of the stiffness-of a single muscle and attempts to explain the mechanics of running. We propose to use an inverse dynamics approach that begins by focusing on the link between locomotion mechanics and overall musculoskeletal stiffness. Under the umbrella of Specific Aim 1, the importance of adjustments to the stiffness of the overall musculoskeletal system to accommodate running on varied terrain is examined. This research will involve examining the adjustments to musculoskeletal stiffness for running on surfaces of different stiffnesses and surfaces of varying predictability. Under the umbrella of Specific Aim 2, we will do a series of interrelated studies examining the mechanisms for adjusting the stiffness of the overall musculoskeletal system during running. These studies will include examining the range over which the stiffness of a single joint of the leg can be adjusted during locomotion. In addition, it will involve examining the relative importance of changes to joint stiffness and posture in adjusting the stiffness of the overall musculoskeletal system during running. The experiments under both Specific Aims l and 2 will involve a combined kinetic and kinematic analysis of running to determine overall musculoskeletal stiffness and joint stiffness. The findings will give new information about the optimal design of floors and tracks for minimizing overuse injuries during sustained weight-bearing aerobic activities, and the optimal design of spring-based prosthetic legs and robotic legs. Finally, our research will begin applying knowledge of the neural control of joint stiffness to understanding the mechanics of a natural activity that is performed by all legged animals, locomotion.