US-German Collaboration: Testing Muscle Synergies in a Neuromechanical Rat Model for Nominal and Perturbed Locomotion

这个项目的重点是神经和生物力学的原则，导致在运动过程中的动态稳定性。通过更好地了解哺乳动物脊髓回路，可以改善对影响平衡和协调的神经系统疾病（例如脊髓损伤，中风，帕金森氏症）的医疗和诊断。神经机械模型还将激发对机械系统和辅助外骨骼控制器设计的改进，以提高人类的稳定性和移动性。举例来说，此神经模型可有效用于与外骨骼的电机的控制及与人的完整系统协同地控制人的肌肉。从这项工作中得到的控制系统也可以提供自主腿机器人更大的机动性和适应性的运动在未知的地形。 该项目还将涉及神经生物学、动物学、机械工程和系统控制交叉领域的国际合作和跨学科教育与培训。为了更好地了解哺乳动物神经系统如何处理多感官反馈，以动态控制后腿的多个自由度，研究人员将：1）使用同步双平面X射线摄像、测力板和肌电图记录来测量大鼠在各种环境中跑步的运动学、地面反作用力和肌肉激活（不同速度和灵活性的研磨机，以及在具有意外干扰（例如孔、活板门和移动的地面条件）的基底上）; 2）使用这些数据扩展大鼠的矢状面生物力学模型和基于传导的神经模型，以在三维中产生后肢的自立行走; 3）通过探索不同的组织模型和测试这些模型适应扰动和保持步行行为的动态控制的能力来研究协同肌肉群的控制机制。一个配套项目正在由德国的联邦教育和研究部（BMBF）资助。

This project focuses on the neural and biomechanical principles that result in dynamic stability during locomotion. Medical treatments and diagnosis for neurological conditions that affect balance and coordination (e.g. spinal cord injury, stroke, Parkinson's) can be improved with a better understanding of mammalian spinal cord circuits. Neuromechanical models will also inspire improvements to the design of mechanical systems and controllers for assistive exoskeletons for human stability and mobility. For example, such a neural model could be effective for controlling a person's muscles in tandem with control of an exoskeleton's motors and with the person's intact systems. Control systems derived from this work may also provide autonomous legged robots greater mobility and adaptability for movement in unknown terrain. This project will also involve international collaboration and interdisciplinary education and training at the intersection of neurobiology, zoology, mechanical engineering, and system control.To better understand how the mammalian nervous system processes multi-sensory feedback for dynamic control of the many degrees of freedom in the rear legs, the investigators will: 1) Use simultaneous two-plane X-ray videography, force plates and EMG recordings to measure the kinematics, ground reaction forces, and muscle activations of rats running in various environments (treadmills of different speeds and flexibility, and on substrates with unexpected disturbances such as holes, a trapdoor and a shifting ground condition); 2) Use these data to expand a sagittal plane biomechanical model and conductance-based neural model of the rat to produce self-supporting walking of the hind legs in three dimensions; and 3) Investigate mechanisms for control of synergistic muscle groups by exploring different organizational models and testing the capability of these models for adapting to perturbations and maintaining dynamic control of walking behavior.A companion project is being funded by the Federal Ministry of Education and Research, Germany (BMBF).