Preface

Proprioception represents a conspicuous part of the somatosensory system. The actual state of the art in the study of proprioception clearly demonstrates that it is a field of continuous active and innovative research. A large body of evidence has been accumulated in the last years concerning the characteristics of proprioceptors and the peripheral sensory organs connected to them (i.e., muscle spindles and Golgi's tendon organs). Furthermore, the contribution to proprioception of mechanoreceptors situated in the joint capsule and skin is being actively explored.

*Proprioception* is a collection of reviews and new information on mechanosensitivity. We hope it will be of interest for investigators in basic research, as well as for clinicians with an interest in proprioception.

In the opening chapter, "Structural and Biological Basis for Proprioception," the editors, José A. Vega and Juan Cobo summarize and update the basics of the topic, knowledge on muscle proprioceptors (i.e., muscle spindles), mechanisms and molecular bases for mechanotransduction in muscle spindles, pathways of proprioception, and the clinical importance of proprioception. This chapter provides the common foundations that make it easier to read the subsequent chapters of the book.

The second chapter, "Proprioception and Clinical Correlation" by Pinar Gelener, Gözde İyigün, and Ramadan Özmanevra, focuses on the anatomy, motor control, and postural control related to proprioception with neurologic clinical correlation. It also contains information about the changes in joint proprioception after orthopedic surgeries.

The following two chapters discuss proprioception in the lower extremities. The third chapter, "Recording of Proprioceptive Muscle Reflexes in the Lower Extremity" by Juhani Partanen, Urho Sompa, and Miguel Muñoz-Ruiz, analyzes the proprioceptive reflexes, especially the H-reflex, and recommends recording of this reflex with an EMG needle electrode to perform accurate diagnostics.

The fourth chapter, "The Knee Proprioception as Patient-Dependent Outcome Measures within Surgical and Non-Surgical Interventions" by Wangdo Kim, approaches the problems of proprioception in patients undergoing knee surgical procedures. The authors develop an "evidence-based medicine" design and describe the steps to identify measurable invariants in the knee proprioception system and develop a mathematical framework for outcome measurement within the knee.

The proprioception of the muscles of the head is still an open matter since the nerves driving the information to the central nervous system are not definitively identified and most cephalic muscles lack muscle spindles, which are the true

proprioceptors. The fifth chapter, "Proprioceptors in Cephalic Muscles" by Juan L. Cobo, Sonsoles Junquera, José Martín-Cruces, Antonio Solé-Magdalena, Olivia García-Suárez, and Teresa Cobo, explores the presence of alternative or atypical proprioceptors in head muscles. The authors identify three basic types of possible atypical proprioceptors based on the expression of PIEZO2 and ASIC2 mechanoproteins and establish the relative densities of each type in the muscles analyzed.

The sixth chapter, "Proprioception Impairment and Treatment Approaches in Pediatrics" by Kamatchi Kaviraja, introduces the new aspect of proprioception sense and its dysfunction. The author focuses on children with behavioral problems in which early identification and intervention play major roles in improving the ability and development of the proprioceptive senses.

The seventh chapter, "Proprioceptive Perception: An Emergence of the Interaction of Body and Language" by Alejandra Vasquez-Rosati and Carmen Cordero-Homad, provides a systemic perspective of human behavior, which reformulates the concept of effective behavior and cognition that derive from the classical vision of neuroscience and psychology based on the Cartesian reductionist functionalist paradigm. This chapter answers the question of how proprioceptive perception affects human beings' experience of being different from others and from the environment and it explains how this phenomenon modulates.

The chapter "Nomophobia Kids and Proprioception" by Giridharan Vaishnavi analyzes the impact of nomophobia (*the soreness or tension as a result of the non-availability of a cellular telephone, a personal laptop or any some other digital verbal exchange device*) on proprioception, especially in kids. Children using smartphones for a long time experience a great impact on the sensorimotor function with a deficit in proprioception.

In the last chapter, "Proprioception in Immersive Virtual Reality," Alexander Vladimirovich Zakharov, Alexander Vladimirovich Kolsanov, Elena Viktorovna Khivintseva, Vasiliy Fedorovich Pyatin, and Alexander Vladimirovich Yashkov drive the readers to a new, innovative, and almost futuristic projection of proprioception: its connection to virtual reality (VR). Under the conditions of VR, a variety of multimodal sensory experiences can be obtained, and in the opinion of the authors it is necessary and urgent to create immersive explicit environments to bring the full potential of VR technology powers. Activation of the proprioceptive system, coupled with the activation of the visual analyzer system, allows achieving sensations of interaction with VR objects, identical to the sensations of the real physical world. These new devices must be readily available for use in routine medical practice, customizing the rehabilitation process for different pathologies.

Each of the book's chapters represents the efforts of diverse specialists to analyze and review recent findings on several aspects of proprioception. We thank the authors for their collaboration, their effort, and their competence. Finally, we express our thanks to Mr. Josip Knapic and IntechOpen for their invaluable support and editorial assistance. We are also very grateful to the

**V**

professors who served as reviewers for the chapters. We hope this book will be of interest for investigators in basic research as well as clinicians with an interest in

**José A. Vega**

Spain

Chile

Spain

**Juan Cobo**

Oviedo, Spain

Grupo SINPOS,

Universidad de Oviedo,

Universidad de Oviedo,

Facultad de Ciencias de la Salud, Universidad Autónoma de Chile,

Instituto Asturiano de Odontología,

Departamento de Morfología y Biología Celular,

Departamento de Cirugía y Especialidades Médico-Quirúrgicas,

proprioception.

professors who served as reviewers for the chapters. We hope this book will be of interest for investigators in basic research as well as clinicians with an interest in proprioception.

> **José A. Vega** Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Spain

> > Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Chile

**Juan Cobo** Departamento de Cirugía y Especialidades Médico-Quirúrgicas, Universidad de Oviedo, Spain

> Instituto Asturiano de Odontología, Oviedo, Spain

**IV**

different pathologies.

analyzed.

modulates.

proprioceptors. The fifth chapter, "Proprioceptors in Cephalic Muscles" by Juan L. Cobo, Sonsoles Junquera, José Martín-Cruces, Antonio Solé-Magdalena, Olivia García-Suárez, and Teresa Cobo, explores the presence of alternative or atypical proprioceptors in head muscles. The authors identify three basic types of possible atypical proprioceptors based on the expression of PIEZO2 and ASIC2 mechanoproteins and establish the relative densities of each type in the muscles

The sixth chapter, "Proprioception Impairment and Treatment Approaches in Pediatrics" by Kamatchi Kaviraja, introduces the new aspect of proprioception sense and its dysfunction. The author focuses on children with behavioral problems in which early identification and intervention play major roles in improving the

The chapter "Nomophobia Kids and Proprioception" by Giridharan Vaishnavi analyzes the impact of nomophobia (*the soreness or tension as a result of the non-availability of a cellular telephone, a personal laptop or any some other digital verbal exchange device*) on proprioception, especially in kids. Children using smartphones for a long time experience a great impact on the sensorimotor

In the last chapter, "Proprioception in Immersive Virtual Reality," Alexander Vladimirovich Zakharov, Alexander Vladimirovich Kolsanov, Elena Viktorovna Khivintseva, Vasiliy Fedorovich Pyatin, and Alexander Vladimirovich Yashkov drive the readers to a new, innovative, and almost futuristic projection of proprioception: its connection to virtual reality (VR). Under the conditions of VR, a variety of multimodal sensory experiences can be obtained, and in the opinion of the authors it is necessary and urgent to create immersive explicit environments to bring the full potential of VR technology powers. Activation of the proprioceptive system, coupled with the activation of the visual analyzer system, allows achieving sensations of interaction with VR objects, identical to the sensations of the real physical world. These new devices must be readily available for use in routine medical practice, customizing the rehabilitation process for

Each of the book's chapters represents the efforts of diverse specialists to analyze and review recent findings on several aspects of proprioception. We thank the authors for their collaboration, their effort, and their competence. Finally, we express our thanks to Mr. Josip Knapic and IntechOpen for their invaluable support and editorial assistance. We are also very grateful to the

The seventh chapter, "Proprioceptive Perception: An Emergence of the Interaction of Body and Language" by Alejandra Vasquez-Rosati and Carmen Cordero-Homad, provides a systemic perspective of human behavior, which reformulates the concept of effective behavior and cognition that derive from the classical vision of neuroscience and psychology based on the Cartesian reductionist functionalist paradigm. This chapter answers the question of how proprioceptive perception affects human beings' experience of being different from others and from the environment and it explains how this phenomenon

ability and development of the proprioceptive senses.

function with a deficit in proprioception.

**1**

**Chapter 1**

**Abstract**

Proprioception

*José A. Vega and Juan Cobo*

Structural and Biological Basis for

The proprioception is the sense of positioning and movement. It is mediate by proprioceptors, a small subset of mechanosensory neurons localized in the dorsal root ganglia that convey information about the stretch and tension of muscles, tendons, and joints. These neurons supply of afferent innervation to specialized sensory organs in muscles (muscle spindles) and tendons (Golgi tendon organs). Thereafter, the information originated in the proprioceptors travels throughout two main nerve pathways reaching the central nervous system at the level of the spinal cord and the cerebellum (unconscious) and the cerebral cortex (conscious) for processing. On the other hand, since the stimuli for proprioceptors are mechanical (stretch, tension) proprioception can be regarded as a modality of mechanosensitivity and the putative mechanotransducers proprioceptors begins to be known now. The mechanogated ion channels acid-sensing ion channel 2 (ASIC2), transient receptor potential vanilloid 4 (TRPV4) and PIEZO2 are among candidates. Impairment or poor proprioception is proper of aging and some neurological diseases. Future research should focus on treating these defects. This chapter intends provide a comprehensive update an overview of the anatomical, structural and molecular basis of proprioception as well as of the main causes of propriocep-

tion impairment, including aging, and possible treatments.

proprioceptive pathways, spinocerebellar tracts

**1. Introduction**

**Keywords:** proprioception, muscle spindles, mechanotransduction, ion channels,

Proprioception is a wider sense, that include position and movement of parts of the body relative to one another, and the force and effort associated with muscle contraction and movement. But properly the term *proprioception* applies for the sensory information contributing to sense of self position, whereas *kinesthesis* refers of sense of movement. The first one is regarded as an automatic function and unconscious in contrast with the second one considered as conscious. In the words of Kröger and Watkins [1] "*Proprioceptive information informs us about the contractile state and movement of muscles, about muscle force, heaviness, stiffness, viscosity and effort and, thus, is required for any coordinated movement, normal gait and for the maintenance of a stable posture*". This information travels to the central nervous system, but differently to other components of somatosensitivity, a great part of the proprioceptive sense does not reach consciousness. This is probably due to suppression as a consequence of the motor signals [2] or inhibitions along somatosensory pathways [3]. The precise knowledge of the pathways of proprioception, especially
