Control of finger movement and force for precision pinch

描述(申请人提供)：多指操作需要众多肌肉之间的相互作用，以产生必要的指尖运动和力量。手指的肌肉(包括拇指)被认为是多余的。冗余度长期以来一直被称为运动控制的核心问题，它还表明对某些肌肉的丧失具有健壮性。到目前为止，我们的工作迫使并使我们能够系统地建立手指内肌肉之间的相互作用，以及抓握中的手指之间的相互作用，如何对肌肉功能障碍保持健壮。每个假设和目标都涉及多指抓握的一个基本组成部分的产生，但目前尚不清楚：手指缓慢运动和抓握平衡。为了检验每个假设，我们将应用和扩展我们的综合方法，将行为研究、身体实验、数学分析和生物力学建模结合在两个相辅相成的目标上。目的1：描述手指肌肉运动所必需的力学相互作用，并量化其对特定肌肉丧失的稳健性。我们将重点研究肌腱张力如何影响拇指、食指和中指缓慢动作获得抓握的可行性。假设一：抓握的获得和释放缺乏冗余性：缓慢的手指运动对某些肌肉的丧失不是很健壮。目的2：描述多指抓握平衡所必需的肌腱张力之间的相互作用，并量化它们对特定肌肉丧失的稳健性。我们将专注于单个肌肉的张力如何影响两指和三指精确抓取的平衡(使用拇指：食指；和拇指：食指：中指)。我们还将探索模拟的信号相关噪声如何影响抓取平衡。基本假设IIa：静态抓握力缺乏冗余性：抓握平衡对某些肌肉的丧失不是很稳健。第二假设IIb：静态抓取力缺乏冗余性：肌肉信号依赖的噪声进一步损害抓取平衡。本项目对多指抓握的了解将为了解灵活手法在特定骨科/神经疾病、发育和衰老中的脆弱性(和康复)提供亟需的神经力学基础。 与公共健康相关：使用我们的手指抓住和握住物体是我们进行大多数日常生活活动所必需的。然而，由于手的解剖结构如此复杂，人们对手指的每一块肌肉如何参与抓取功能知之甚少。我们提议的项目将结合解剖学、工程学和临床知识，确定哪些肌肉最重要，因此应该受到最大的保护，以改善手部多种残疾患者的手功能。

DESCRIPTION (provided by applicant): Multifinger manipulation requires interactions among numerous muscles to produce the necessary fingertip motions and forces. The muscles of the fingers (including the thumb) are considered redundant. Redundancy, which has long been called the central problem of motor control, also suggests robustness to loss of some muscles. Our work to date compels and enables us to systematically establish how the interactions among muscles within a finger, and the fingers within a grasp, fail to be robust to muscle dysfunction. Each Hypothesis and Aim addresses the production of a fundamental, yet currently not understood, component of multifinger grasp: slow finger motions and grasp equilibrium. To test each Hypothesis we will apply and extend our integrative approach combining behavioral studies, cadaveric experiments, mathematical analysis, and biomechanical modeling in two complementary Aims. Aim 1: Characterize the necessary mechanical interactions among finger muscles for motion; and quantify their robustness to loss of specific muscles. We will focus on how tendon tensions affect the feasibility of slow motions of the thumb, index and middle fingers for grasp acquisition. Hypothesis I: Lack of redundancy for grasp acquisition and release: Slow finger motions are not robust to loss of some muscles. Aim 2: Characterize the necessary interactions among tendon tensions for multifinger grasp equilibrium; and quantify their robustness to loss of specific muscles. We will focus on how tensions from individual muscles affect the equilibrium of two- and three-finger precision grasps (using the tips of thumb:index; and thumb:index:middle). We will also explore how simulated signal-dependent noise affects grasp equilibrium. Primary Hypothesis IIa: Lack of redundancy for static grasp forces: Grasp equilibrium is not robust to loss of some muscles. Secondary Hypothesis Hypothesis IIb: Lack of redundancy for static grasp forces: Muscle Signal-Dependent Noise further compromises grasp equilibrium. The understanding gained about multifinger grasp in this project will provide the much-needed neuro-mechanical foundation to understand the vulnerability (and rehabilitation) of dexterous manipulation in specific orthopedic/neurologic diseases, development and aging. PUBLIC HEALTH RELEVANCE: Using our fingers to grasp and hold objects is necessary for us to perform most of our activities of daily living. However, because the anatomy of the hand is so complex, there is little known about how each muscle of the fingers contributes to grasping function. Our proposed project will combine anatomical studies, engineering science and clinical know-how to establish which muscles are most important, and therefore should be most protected, to improve the hand function of people suffering from the many disabilities of the hand.