Biomechanical Principles on Force Generation and Control of Skeletal Muscle and their Applications in Robotic Exoskeleton

Yuehong Yin

• Publisher: CRC Press
• Year: 2019
• ISBN:
  9781000649963
• Edition: 1
• Topic: Computer Science
• Subtopic: Information Technology
• Index: Computer Science

This book systematically introduces the bionic nature of force sensing and control, the biomechanical principle on mechanism of force generation and control of skeletal muscle, and related applications in robotic exoskeleton.

The book focuses on three main aspects: muscle force generation principle and biomechanical model, exoskeleton robot technology based on skeletal muscle biomechanical model, and SMA-based bionic skeletal muscle technology.

This comprehensive and in-depth book presents the author's research experience and achievements of many years to readers in an effort to promote academic exchanges in this field.

About the Author

Yuehong Yin received his B.E., M.S. and Ph.D. degrees from Nanjing University of Aeronautics and Astronautics, Nanjing, in 1990, 1995 and 1997, respectively, all in mechanical engineering. From December 1997 to December 1999, he was a Postdoctoral Fellow with Zhejiang University, Hangzhou, China, where he became an Associate Professor in July 1999. Since December 1999, he has been with the Robotics Institute, Shanghai Jiao Tong University, Shanghai, China, where he became a Professor and a Tenure Professor in December 2005 and January 2016, respectively. His research interests include robotics, force control, exoskeleton robot, molecular motor, artificial limb, robotic assembly, reconfigurable assembly system, and augmented reality. Dr. Yin is a fellow of the International Academy of Production Engineering (CIRP).

1	Force Generation Mechanism of Skeletal Muscle Contraction

In a narrow sense, the aim of studies on the mechanism of force generation of skeletal muscle is to give theoretical explanations to the dynamic characteristics and phenomena of muscular contraction and to promote the relevant experimental researches in an iterative way of verification and correction. In a broad sense, it aims to provide theoretical guidance to practical applications in the fields such as biomechanics and biomedicine, including diagnosis and evaluation of muscle diseases, human–machine integrated coordinated control of exoskeleton robots, dynamic modeling of human motion, bionic design of artificial muscle and humanoid robot, etc. Thus, there are both great theoretical significance and wide application foreground concerning the study of force generation mechanism of skeletal muscle.

In this field, the earliest breakthroughs were made by Hill [1] and Huxley [2], both of them Nobelists. Their work laid the foundation for the study on mechanism of muscular contraction. Recently, with the development of micro/nano technology and single-molecule manipulation technique, deeper understandings were achieved about the microscopic mechanism of skeletal muscle contraction. Physiology, physical chemistry, molecular biology, statistical thermodynamics, cybernetics, nonlinear mathematics, etc., are all involved in the study of force generation mechanism of skeletal muscle, which is typical interdisciplinary research. In consequence, both the degrees of complexity and difficulty are very high, resulting in theoretical and technical challenges. In this chapter, the morphological structure of skeletal muscle under various scales is introduced first. On that basis, the biomechanical principle of muscular contraction, i.e., the excitation–contraction coupling (ECC) process, is systematically illustrated. Finally, receptors in skeleton muscle and proprioceptive feedback of human motion are discussed, aiming to provide readers with elementary-to-profound understanding of the mechanism and process of skeletal muscle contraction.

1.1ANATOMY OF SKELETAL MUSCLE

For a biological system, structure and function are inseparable; i.e., most of the functions are basically determined by its structure. Thus, the activities of skeletal muscle contraction are based on its particular structure. An overall comprehension of its structure from macroscopic to microscopic is necessary in the first place, in order to have deeper understanding on the mechanism of contraction and force generation. In this book, the spatial scale is divided as follows: macroscopic scale (greater than 10² μm), mesoscopic scale (10⁻¹–10² μm), and microscopic scale (less than 10⁻¹ μm).

1.1.1MACROSTRUCTURE

The macrostructure of skeletal muscle is illustrated in Figure 1.1a. According to the above scale division, the macrostructure scales from muscle to single fascicle. A muscle is wrapped up by epimysium consisting of blood vessels and nervous tissues. The epimysium goes into the muscle and divides it into fascicle tissues. Each fascicle, wrapped by epimysium, consists of tens or hundreds of muscle fibers, i.e., the myocyte. Thus, the maximum diameter of fascicle is approximately several hundred μm. There are different morphologies of skeleton muscle, such as paralleled muscle, musculi fusiformis, single-pennate muscle and multi-pennate muscle, etc., depending on various fiber arrangements. Payne angle and physiological cross-sectional area are the two parameters that are often used to describe muscle’s structural characteristics. Payne angle is the angle between fiber and tendon, while the physiological cross-sectional area is the maximum cross-sectional area of muscle. Thus, the bigger the area is, the more muscle fibers in the muscle.

FIGURE 1.1 Skeletal muscle under different space scales (from left to right): (a) macrostructure; (b) mesostructure; (c) microstructure—thin filament; (d) microstructure—thick filament; (e) microstructure—head group of molecular motor.

1.1.2MESOSTRUCTURE

The mesostructure of skeletal muscle is illustrated in Figure 1.1b. It ranges from fiber to sarcomere. Skeletal muscle mainly consists of parallel fibers, which are connected by endomysium and wrapped by sarcolemma with a diameter of about 1–2 μm. Inside the sarcolemma, there are tens or hundreds of myofibrils. Tissues, such as motion proprioceptor, neuromuscular junction, and the opening of transverse tubule (T-tubule), are adhered to the sarcolemma. Each myofibril, wrapped by sarcoplasmic reticulum (SR), consists of many sarcomeres in series, each of which is surrounded by two rings of T-tubules.

1.1.3MICROSTRUCTURE

FIGURE 1.2 (a) Horizontal structure of sarcomere; (b) vertical structure of sarcomere.

The microstructure of skeletal muscle refers to the structure of sarcomere, including the thin filament (Figure 1.1c), thick filament (Figure 1.1d) and myosin motor (also called as molecular motor) (Figure 1.1e). The horizontal and vertical spatial relationships are illustrated in Figure 1.2a,b. M-line has been recognized as the center of sarcomere. Thick filaments start from the M-line and extend to both ends of sarcomere. Thin filaments start from the Z-line at the two extremes of sarcomere and extend to the M-line. Thus, the thin and thick filaments overlap with each other. The thin filament, also called as actin filament, mainly consists of single actins in the form of α-double helix. Tropomyosin (Tm) and troponin (Tn) twine around the thin filaments periodically. The thick filament is formed by the tails of molecular motor twining with each other. The molecular motor binds with thin filaments periodically, consuming the energy released by the hydrol...

Table of contents

• Cover
• Half Title
• Series Page
• Title Page
• Copyright Page
• Table of Contents
• Foreword
• Author
• Chapter 1 Force Generation Mechanism of Skeletal Muscle Contraction
• Chapter 2 Biomechanical Modeling of Muscular Contraction
• Chapter 3 Estimation of Skeletal Muscle Activation and Contraction Force Based on EMG Signals
• Chapter 4 Human–Machine Force Interactive Interface and Exoskeleton Robot Techniques Based on Biomechanical Model of Skeletal Muscle
• Chapter 5 Clinical Rehabilitation Technologies for Force-Control–Based Exoskeleton Robot
• Chapter 6 Bionic Design of Artificial Muscle Based on Biomechanical Models of Skeletal Muscle
• Conclusion
• Index