Neuromuscular generation and control of force output in humans

这项研究计划的重点是确定影响人类肌肉力量产生和控制的关键因素。通过使用综合系统水平的方法，主要目标是继续提供这一领域的重要信息，既适用于基本系统生理学，也适用于应用生理学。核心技术允许重点关注在运动的产生和自愿控制期间中枢神经驱动和肌肉收缩特征之间的相互关系。人体模型为推进这一领域的知识提供了几个重要机会。参与者可以完成各种必要的任务，这些任务反映了依赖于整个整合系统中有效的肌肉力量产生和控制的正常活动。这些措施包括从运动皮质、脊髓和周围神经系统到骨骼肌的内在特性(包括数量(解剖学)和质量(生理学))的各个层面的评估。*神经和肌肉特性之间的匹配使人体能够在给定条件下优化运动，这个正在进行的计划正在探索这种关系和它的适应性。实验包括研究急性(疲劳、增强)和慢性适应状态(衰老、训练)作为模型，结合几种创新技术，提供全面的信息，从中可以获得对人类神经肌肉和肌肉骨骼系统的综合了解。*从几个相互关联的研究中，本提案概述的一般焦点包括：*1)动态(缩短/延长)收缩过程中运动单位特性(重新招募和速率编码)的控制，与目前大多数从等长(静态长度)收缩获得的理解相比。2)使用状态改变的模型(衰老)，以更好地理解神经驱动和肌肉反应之间的独特关系，并重新强调神经肌肉连接的电生理学评估。3)疲劳引起的短期(瞬时)自然变化如何影响神经驱动和收缩功能之间的关系？*该计划中值得注意的是几种微创技术的独特组合，无论是在我们的实验室内还是通过建立的合作关系，这些问题都可以用现有的技术彻底解决。这些包括运动单位电生理学的所有方面；神经肌肉系统的外周(电)激活；自愿力或扭矩(等长和动态)的测量；肌肉的超声波和磁共振成像。

This research program has had a focus on determining key factors affecting the generation and control of muscle force in humans. By using an integrative systems level approach the primary objective is to continue to provide important information in this field that is applicable to both fundamental systems physiology and applied physiology. Core techniques permit a focus on the interrelationship between central neural drive and muscle contractile characteristics during the generation and voluntary control of movement. The human model offers several important opportunities for advancing knowledge in this area. Participants can comply with various requisite tasks that reflect normal activities that are dependent on effective muscle force generation and control in the integrated whole system. These include assessing the system at various levels from the motor cortex, spinal cord and peripheral nervous system to intrinsic properties of skeletal muscle including quantity (anatomy) and quality (physiology).*** Matching between neural and muscular properties allows the human body to optimize movement for a given condition, and this ongoing program is exploring this relationship and it's adaptability. Experiments involve studying acute (fatigue, potentiation) and chronic adapted states (aging, training) as models with a combination of several innovative techniques that provide comprehensive information from which an integrative understanding of the human neuromuscular and musculoskeletal systems can be gained. ***From several inter-related studies general foci outlined in this proposal include: ****1) Control of motor unit properties (recruitment and rate coding) during dynamic (shortening/lengthening) contractions as compared with most all current understanding which has been gained from isometric (static length) contractions. 2) Using models of altered states (aging) to better understand the unique relationship between neural drive and muscle responses with a new emphasis on the neuromuscular junction assessed electrophysiologically. 3) How do short term (transient) natural changes induced by fatigue affect the relationship between neural drive and contractile function?*** Notable in the program is the unique combination of several minimally invasive techniques either within our laboratory or through established collaborations which allow these questions to be addressed thoroughly with current technologies. These include all aspects of motor unit electrophysiology; peripheral (electrical) activation of the neuromuscular system; measures of voluntary force or torque (isometric and dynamic); ultrasound and magnetic resonance imaging of muscle.**