Therapeutic Modalities For Sports Medicine and Athletic Training William

SIXTH TherapeuticEDITION Modalities for Sports Medicine and Athletic Training WILLIAM E. PRENTICE SIXTH EDITION

Therapeutic Modalities



Sixth Edition Therapeutic Modalities For Sports Medicine and Athletic Training William E. Prentice, Ph.D., A.T.C., P.T. Professor, Coordinator of Sports Medicine Specialization, Department of Exercise and Sport Science The University of North Carolina at Chapel Hill Chapel Hill, North Carolina Boston Burr Ridge, IL Dubuque, IA Madison, WI New York San Francisco St. Louis Bangkok Bogotá Caracas Kuala Lumpur Lisbon London Madrid Mexico City Milan Montreal New Delhi Santiago Seoul Singapore Sydney Taipei Toronto

Published by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2009, 2003, 1999, 1994, 1990, 1986 by The McGraw-Hill Companies, Inc. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 DOC/DOC 1 0 9 8 ISBN: 978-0-07-304519-1 MHID: 0-07-304519-5 Editor-in-Chief: Michael Ryan Publisher: William R. Glass Executive Editor: Christopher Johnson Marketing Manager: Bill Minick Director of Development: Kathleen Engelberg Developmental Editor: Gary O’Brien, VanBrien & Associates Developmental Editor for Technology: Julia D. Akpan Lead Media Project Manager: Ronald Nelms, Jr. Production Editor: Karol Jurado Production Service: Jill Eccher Manuscript Editor: Ginger Rodriguez Text and Cover Designer: Ashley Bedell Cover Image: © PhotoLink/Getty Images Lead Production Supervisor: Randy Hurst Composition: 10/12 Photina by Aptara®, Inc. Printing: 45# New Era Matte Plus, R.R. Donnelley & Sons Credits: The credits section of this book begins on page C-1 and is considered an extension of the copyright page. Library of Congress Cataloging-in-Publication Data Therapeutic modalities : for sports medicine and athletic training / [edited by] William E. Prentice. —6th ed. p. : cm. Includes bibliographical references and index. ISBN-13: 978-0-07-304519-1 (alk. Paper) ISBN 0–07–304519–5 (alk. paper) 1. Sports injuries—Treatment. 2. Sports physical therapy. 3. Athletic trainers. I. Prentice, William E. II. Therapeutic modalities in sports medicine. [DNLM: 1. Athletic Injuries—therapy. 2. Athletic Injuries—rehabilitation. 3. Physical Therapy Modalities. QT 261 T398 2009] RD97 .T484 2009 617.1’027—dc22 2008009203 The Internet addresses listed in the text were accurate at the time of publication. The inclusion of a Web site does not indicate an endorsement by the authors or McGraw-Hill, and McGraw-Hill does not guarantee the accuracy of the information presented at these sites. www.mhhe.com

Brief Contents Preface xi PART FOUR Sound Energy Modalities Contributors xv Chapter 8 Therapeutic Ultrasound PART ONE Foundations of Therapeutic PART FIVE Eletromagnetic Energy Modalities Modalities Chapter 1 The Basic Science of Therapeutic Chapter 9 Low-level Laser Therapy Modalities Chapter 10 Shortwave and Microwave Chapter 2 Using Therapeutic Modalities to Diathermy Affect the Healing Process PART SIX Mechanical Energy Modalities Chapter 3 Managing Pain with Therapeutic Modalities Chapter 11 Intermittent Compression Devices PART TWO Thermal Energy Modalities Chapter 12 Spinal Traction Chapter 4 Cryotherapy and Thermotherapy Chapter 13 Therapeutic Sports Massage PART THREE Electrical Energy Modalities Chapter 5 Basic Principles of Electricity and Electrical Stimulating Currents Chapter 6 Iontophoresis Chapter 7 Biofeedback v



Detailed Contents Preface xi The Importance of Understanding the Healing Process 19 Contributors xv Inflammatory-Response Phase 19 PART ONE Foundations of Therapeutic Fibroplastic-Repair Phase 22 Modalities Maturation-Remodeling Phase 23 Factors That Impede Healing 24 1 The Basic Science of Therapeutic How Should Therapeutic Modalities Be Used Modalities 2 throughout the Rehabilitation Process? 25 Using Modalities in the Immediate First Aid William E. Prentice and Bob Blake Management of Injury 25 Forms of Energy 2 Modality Use in the Inflammatory-Response Electromagnetic Energy 3 Phase 27 The Relationship between Wavelength and Modality Use in the Fibroblastic-Repair Phase 27 Frequency 4 Modality Use in the Maturation-Remodeling The Electromagnetic Energy Spectrum 4 Phase 28 How Is Electromagnetic Energy Produced? 6 Other Considerations in Treating Injury 29 Effects of Electromagnetic Radiations 7 Summary 29 Laws Governing the Effects of Electromagnetic 3 Managing Pain with Therapeutic Energy 7 Electromagnetic Energy Modalities 9 Modalities 33 Thermal Energy 10 Thermal Energy Modalities 11 Craig R. Denegar and William E. Prentice Electrical Energy 11 Electrical Energy Modalities 12 Understanding Pain 33 Sound Energy 12 Types of Pain 34 Sound Energy Modalities 12 Mechanical Energy 13 Pain Assessment 34 Mechanical Energy Modalities 13 Pain Assessment Scales 35 Summary 14 Goals in Pain Management 38 2 Using Therapeutic Modalities to Affect Pain Perception 38 the Healing Process 17 Sensory Receptors 38 Cognitive Influences 40 William E. Prentice Neural Transmission 40 Facilitators and Inhibitors of Synaptic How Should the Athletic Trainer Use Therapeutic Modalities in Rehabilitation? 17 Transmission 41 Nociception 43 Neurophysiological Explanations of Pain Control 44 The Gate Control Theory of Pain 45 Descending Pain Controls 45 β-endorphin and Dynorphin in Pain Control 46 Summary of Pain Control Mechanisms 48 Pain Management 48 Summary 49 vii

viii Contents Biostimulative Effects of Electrical Current on Nonexcitatory Cells 129 PART TWO Thermal Energy Modalities Clinical Uses of Electrical Stimulating 4 Cryotherapy and Thermotherapy 55 Currents 129 William E. Prentice High-Volt Currents 129 Asymmetric Biphasic Currents (TENS) 135 Mechanisms of Heat Transfer 57 Russian Currents (Medium-Frequency Current Appropriate Use of Cryotherapy and Thermotherapy Generators) 140 Modalities 57 Interferential Currents 141 Clinical Use of the Conductive Energy Modalities 58 Premodulated Interferential Current 144 Low-Volt Currents 144 Effects of Tissue Temperature Change on Bone Growth Stimulators 145 Circulation 59 Placebo Effect of Electrical Stimulation 145 Safety in the Use of Electrical Equipment 146 Effects of Tissue Temperature Change on Muscle Summary 148 Spasm 60 6 Iontophoresis 166 Effects of Temperature Change on Performance 61 Cryotherapy 62 William E. Prentice Physiologic Effects of Tissue Cooling 62 Iontophoresis versus Phonophoresis 166 177 Cryotherapy Treatment Techniques 65 Basic Mechanisms of Ion Transfer 167 Thermotherapy 78 Physiologic Effects of Tissue Healing 78 Pharmacokinetics of Iontophoresis 167 Thermotherapy Treatment Techniques 79 Movement of Ions in Solution 167 Counterirritants 88 Movement of Ions through Tissue 168 Summary 89 Iontophoresis Equipment and Treatment PART THREE Electrical Energy Modalities Techniques 170 Type of Current Required 170 5 Basic Principles of Electricity and Electrical Iontophoresis Generators 170 Current Intensity 170 Stimulating Currents 104 Treatment Duration 171 Dosage of Medication 171 Daniel N. Hooker and William E. Prentice Electrodes 171 Selecting the Appropriate Ion 173 Components of Electrical Currents 104 Clinical Applications for Iontophoresis 175 Electrotherapeutic Currents 107 Treatment Precautions and Contraindications Generators of Electrotherapeutic Currents 108 Treatment of Burns 177 Waveforms 109 Sensitivity Reactions to Ions 178 Summary 178 Waveform Shape 109 Pulses versus Phases and Direction of 7 Biofeedback 185 Current Flow 110 William E. Prentice Current Modulation 113 Electrical Circuits 115 Electromyography and Biofeedback 185 Series and Parallel Circuits 115 The Role of Biofeedback 186 Current Flow through Biologic Tissues 116 Biofeedback Instrumentation 186 Choosing Appropriate Treatment Parameters 117 Frequency 117 Peripheral Skin Temperature 187 Intensity 118 Finger Phototransmission 187 Duration 118 Skin Conductance Activity 187 Polarity 118 Electromyographic Biofeedback 187 Physiologic Responses to Electrical Current 123 Motor Unit Recruitment 188 Direct and Indirect Physiologic Effects 123 Measuring Electrical Activity 188 Nerve Responses to Electrical Currents 124 Separation and Amplification of Electromyographic Muscular Responses to Electrical Current 127 Activity 189

Converting Electromyographic Activity to Meaningful Contents ix Information 191 Ultrasound and Cold Packs 236 Processing the Electromyographic Signal 191 Ultrasound and Electrical Stimulation 237 Biofeedback Equipment and Treatment Treatment Precautions 238 Guidelines for the Safe Use of Ultrasound Techniques 192 Electrodes 192 Equipment 240 Displaying the Information 194 Summary 240 Clinical Applications for Biofeedback 195 Muscle Reeducation 195 PART FIVE Electromagnetic Energy Modalities Relaxation of Muscle Guarding 196 Pain Reduction 197 9 Low-Level Laser Therapy 256 Treating Neurologic Conditions 197 Summary 198 Ethan Saliba and Susan Foreman-Saliba PART FOUR Sound Energy Modalities Physics 257 Types of Lasers 258 8 Therapeutic Ultrasound 206 Laser Treatment Techniques 259 David O. Draper and William E. Prentice Lasing Techniques 260 Dosage 261 Ultrasound as a Heating Modality 207 Depth of Penetration 262 Transmission of Acoustic Energy in Biologic Clinical Applications for Lasers 263 Wound Healing 263 Tissues 207 Pain 266 Transverse versus Longitudinal Waves 207 Bone Response 266 Frequency of Wave Transmission 208 Suggested Treatment Protocols 266 Velocity 209 Pain 267 Attenuation 209 Wound Healing 268 Basic Principles of Therapeutic Ultrasound 210 Scar Tissue 268 Components of a Therapeutic Ultrasound Edema and Inflammation 268 Safety 268 Generator 210 Precautions and Contraindications 270 Physiologic Effects of Ultrasound 219 Conclusion 270 Summary 270 Thermal Effects 219 Nonthermal Effects 220 10 Shortwave and Microwave Ultrasound Treatment Techniques 221 Diathermy 276 Frequency of Treatment 221 Duration of Treatment 222 William E. Prentice and David O. Draper Coupling Methods 223 Exposure Techniques 224 Physiologic Responses to Diathermy 277 Clinical Applications for Therapeutic Thermal Effects 277 Nonthermal Effects 277 Ultrasound 228 Soft-Tissue Healing and Repair 228 Shortwave Diathermy Equipment 278 Scar Tissue and Joint Contracture 229 Shortwave Diathermy Electrodes 280 Stretching of Connective Tissue 229 Pulsed Shortwave Diathermy 285 Chronic Inflammation 230 Treatment Time 286 Bone Healing 231 Pain Reduction 232 Microwave Diathermy 287 Plantar Warts 232 Clinical Applications for Diathermy 288 Placebo Effects 232 Comparing Shortwave Diathermy and Ultrasound as Phonophoresis 232 Using Ultrasound in Combination with Other Thermal Modalities 289 Diathermy Treatment Precautions, Indications, and Modalities 236 Ultrasound and Hot Packs 236 Contraindications 290 Summary 292

x Contents Duration of Treatment 338 Progressive and Regressive Steps 338 PART SIX Mechanical Energy Modalities Manual Cervical Traction 339 Mechanical Cervical Traction 341 11 Intermittent Compression Devices 304 Indications and Contraindications 342 Summary 343 Daniel N. Hooker 13 Therapeutic Sports Massage 349 The Lymphatic System 305 Purposes of the Lymphatic System 305 William E. Prentice Structure of the Lymphatic System 305 Peripheral Lymphatic Structure and Function 306 The Evolution of Massage as a Treatment Modality 349 Injury Edema 307 Formation of Pitting Edema 307 Physiologic Effects of Massage 350 Formation of Lymphedema 307 Reflexive Effects 351 The Negative Effects of Edema Accumulation 308 Mechanical Effects 351 Treatment of Edema 308 Psychological Effects of Massage 352 Intermittent Compression Treatment Techniques 310 Massage Treatment Considerations and Inflation Pressures 310 Guidelines 352 On-Off Sequence 311 Equipment 354 Total Treatment Time 311 Preparation of the Patient 355 Sequential Compression Pumps 312 Massage Treatment Techniques 356 Patient Setup and Instructions 313 Hoffa Massage 356 Cold and Compression Combination 314 Friction Massage 360 Indications and Contraindications for Use 314 Transverse Friction Massage 361 Summary 316 Connective Tissue Massage 361 Trigger Point Massage 363 12 Spinal Traction 322 Strain–Counterstrain 365 Positional Release Therapy 365 Daniel N. Hooker Active Release Technique 366 371 Myofascial Release 367 The Physical Effects of Traction 322 Graston Technique® 368 Effects on Spinal Movement 322 Rolfing 370 Effects on Bone 323 Trager 371 Effects on Ligaments 323 Indications and Contraindications for Massage Effects on the Disk 324 Summary 372 Effects on Articular Facet Joints 325 Effects on the Muscular System 325 Appendixes A-1 Effects on the Nerves 326 Effects on the Entire Body Part 326 A Location of the Motor Points A-1 B Units of Measure A-5 Traction Treatment Techniques 326 C Answers to Self-Quizzes A-6 Lumbar Positional Traction 327 Inversion Traction 328 Glossary G-1 Manual Lumbar Traction 330 Credits C-1 Index I-1 Level-Specific Manual Traction 331 Unilateral Leg Pull Manual Traction 332 Mechanical Lumbar Traction 332 Patient Setup and Equipment 333 Body Position 334 Traction Force 336 Intermittent versus Sustained Traction 337

Preface HOW DO ATHLETIC TRAINERS strength through the full range. Modalities, though USE THERAPEUTIC MODALITIES? important, are by no means the single most critical factor in accomplishing these objectives. Thera- There is little argument that athletic trainers use peutic exercise that forces the injured anatomic a wide variety of therapeutic techniques in the structure to perform its normal function is the key treatment and rehabilitation of injuries. One of the to successful rehabilitation; however, therapeutic more important aspects of a thorough treatment modalities certainly play an important role in re- regimen often involves the use of therapeutic mo- ducing pain and are extremely useful as an adjunct dalities. At one time or another, virtually all ath- to therapeutic exercise. letic trainers make use of some type of therapeutic modality. This may involve a relatively simple It must be emphasized that the use of thera- technique such as using an ice pack as a first aid peutic modalities in any treatment program is an treatment for an acute injury or more complex inexact science. If you were to ask ten different ath- techniques such as the stimulation of nerve and letic trainers what combination of modalities and muscle tissue by electrical currents. There is no therapeutic exercise they use in a given treatment question that therapeutic modalities are useful program, you would probably get ten different tools in injury rehabilitation. When used appro- responses. There is no way to “cookbook” a treat- priately, these modalities can greatly enhance ment plan that involves the use of therapeutic mo- the patient’s recovery. For the athletic trainer, it dalities. Thus, what this book will attempt to do is is essential to possess knowledge regarding the to present the basis for use of each different type of scientific basis and the physiologic effects of the modality and allow the individual athletic trainer various modalities on a specific injury. When this to make his or her own decisions as to which will theoretical basis is applied to practical experience, be most effective in a given clinical situation. Some it has the potential to become an extremely effec- recommended protocols developed through the tive clinical method. experiences of the contributing authors will be presented. WHAT ROLE SHOULD A MODALITY PLAY IN INJURY FORMAL INSTRUCTION IN REHABILITATION? THE USE OF THERAPEUTIC MODALITIES An effective treatment program includes three pri- mary objectives: (1) management or reduction of The athletic trainer is a highly qualified and well- pain associated with an injury, (2) return of full educated allied health care professional concerned nonrestricted range of movement to an injured part, with the treatment and rehabilitation of injuries. and (3) maintenance or perhaps improvement of It is essential for the programs educating athletic training students to provide classroom instruction xi

xii Preface Comprehensive Coverage of Therapeutic Modalities in a Sports in a wide range of specialty areas including injury Medicine Setting prevention, care and management, injury evalu- ation, and therapeutic treatment and rehabilita- The purpose of this text, as in past editions, is to tion techniques. Formal classroom instruction in provide a theoretically based but practically oriented the use of therapeutic modalities is required in all guide to the use of therapeutic modalities for the Committee for Accreditation of Athletic Training athletic trainer who routinely treats injuries. It is in- Education (CAATE) programs for athletic train- tended for use in advanced courses in athletic train- ing students who intend to pursue a career in ing and sports medicine where various clinically sports medicine. Instruction in the use of thera- oriented techniques and methods are presented. peutic modalities has been specifically identified and mandated in the Athletic Training Educational New to This Edition Competencies prepared by the National Athletic Trainers’ Association. Based on the helpful input we have received from users of the text, the sequencing of the chapters in LEGAL ISSUES IN USING this sixth edition has been reorganized and is based on THERAPEUTIC MODALITIES classifying the modalities according to the type of en- ergy that each modality utilizes to produce a specific The use of therapeutic modalities in the treatment therapeutic effect. In addition, each chapter has been of injuries by individuals with various combina- expanded and updated to include the latest available tions of educational background, certification, and research that has been published in related profes- licensure is currently a controversial issue. Specific sional journals since the last edition was published. laws governing the use of therapeutic modalities by athletic trainers vary considerably from state This edition is divided into six parts. Part One, to state. Many states’ licensure acts have specific “Foundations of Therapeutic Modalities,” begins guidelines that dictate how the athletic trainer in Chapter 1 by discussing the scientific basis for may incorporate therapeutic modalities into the using various therapeutic modalities and grouping treatment regimen. Each athletic trainer should be the modalities according to the type of energy each careful that any use he or she makes of a modality uses. Chapter 2 establishes guidelines for selecting is within the limits allowed by the law of his or her the most appropriate modalities for use in different particular state. I do not intend the athletic trainer phases of the healing process. Chapter 3 discusses to interpret anything in this book as encouraging pain in terms of neurophysiologic mechanisms of him or her to act outside the scope of the laws of pain and the role of therapeutic modalities in pain his or her state. management. Part Two, “Thermal Energy Modali- ties,” includes a discussion of thermotherapy and WHY SHOULD THIS TEXT BE cryotherapy in Chapter 4. Part Three “Electrical USED TO TEACH THE ATHLETIC Energy Modalities,” discusses the basic principles TRAINING STUDENT ABOUT of electricity and electrical stimulating currents THERAPEUTIC MODALITIES? in Chapter 5, iontophoresis in Chapter 6, and bio- feedback in Chapter 7. Part Four, “Sound Energy We hope this sixth edition will continue to be a Modalities,” discusses therapeutic ultrasound in useful tool in the ongoing growth and professional Chapter 8. Part Five, “Electromagnetic Energy Mo- development of the athletic trainer interested in dalities,” discusses low-level laser in Chapter 9 and injury rehabilitation. The following are a number of shortwave and microwave diathermy in Chap- reasons why this text should be adopted for use. ter 10. Part Six, “Mechanical Energy Modalities,”

includes intermittent compression (Chapter 11), Preface xiii spinal traction (Chapter 12), and massage (Chapter 13). Each chapter includes discussions of (1) the individuals has also at one time or another been in- physiologic basis for use, (2) clinical applications, volved with the formal classroom education of the and (3) specific techniques of application. athletic training student. Thus, this text has been de- veloped for the student who will be asked to apply the theoretical basis of modality use to the clinical setting. Based on Scientific Theory Pedagogical Aids This text discusses various concepts, principles, and This text includes the following aids to facilitate its theories that are supported by scientific research, fac- use by students and instructors: tual evidence, and the authors’ previous experience with sports-related injuries. The contributing authors Objectives. These goals are listed at the be- have carefully researched the material presented in ginning of each chapter to introduce students to this text to provide the most up-to-date information the points that will be emphasized. The objectives on the theoretical basis for employing a particular mo- have been rewritten to cover the entire spectrum of dality in a specific injury situation. Additionally, both Bloom’s Taxonomy and thus to challenge the stu- athletic trainers and physical therapists who are con- dent to go beyond knowing and comprehending the sidered experts in their field have carefully reviewed material to be able to apply, analyze, synthesize, and the manuscript for this text to ensure that the material evaluate the important concepts they have learned. reflects factual and current concepts for modality use. Figures and Tables. Essential points of each Timely and Practical chapter are illustrated with clear visual materials. The first edition of this text filled a void that existed Glossary of Key Terms. A glossary of terms for quite some time in the athletic training educa- for quick reference is provided. tion program curriculums. It was the first text ever published that focused on therapeutic modalities Analogies. A series of analogies is presented and their use by athletic trainers in a clinical set- to help the reader more easily comprehend more ting. Since the first edition, several other texts on difficult concepts. therapeutic modalities have been published. How- ever, Therapeutic Modalities for Sports Medicine and Clinical Decision-making Exercises. New Athletic Training continues to provide the student exercises have been added to the previous exercises with a comprehensive resource covering all the in each chapter to help the athletic trainer develop therapeutic modalities an athletic trainer uses. decision-making abilities about how a specific mo- dality may best be used clinically. During the preparation of this sixth edition, as well as previous editions of this text, we have Summaries. The important points or con- received much encouragement from athletic train- cepts of each chapter are succinctly reemphasized ing educators and students regarding the usability in the summary list. of this text in the classroom setting. It should serve as a needed guide for the athletic trainer who is in- Review Questions. A series of questions has terested in knowing not only how to use a modality been developed for each chapter to help the student but also why that particular modality is most effec- review the critical points to remember. tive in a given situation. Self-quizzes. New with this edition is a series The authors who have contributed to this text of objective questions in every chapter that can be have a great deal of clinical experience. Each of these used to prepare for a written examination and to assess student comprehension. Answers are located in Appendix D. References. A list of up-to-date references is provided at the end of each chapter for the student who wishes to read further on the subject being discussed.

xiv Preface Students can find additional information on pre- paring for the certification exam under “Preparing Suggested Readings. A comprehensive list for Certification” at www.mhhe.com/prentice13e. of journal articles and textbooks provides additional information related to the chapter material. ACKNOWLEDGMENTS Case Studies. Several case studies have been Since the first edition, many individuals have col- added to each chapter to help illustrate how modali- lectively contributed to the evolution of this text. ties can be incorporated in a treatment regimen in a All have contributed in their own way, but a few variety of patient populations to achieve a treat- deserve special thanks. ment outcome. These studies have been prepared by Sandy Quillen and Frank Underwood. Gary O’Brien, my developmental editor, and Jill Eccher, my project manager, have been responsible Appendixes. A chart of motor points, a table for coordinating the efforts between the publisher for unit conversions, and answers to the self-quizzes and me. As always, they have been very supportive are provided. and have taken care of many of the details in the completion of this text. ANCILLARIES I would like to thank William “Sandy” Quillen Instructor’s Website and Frank Underwood for their help over the years in preparing and updating the case studies. Also, PowerPoint Presentation. Jason Scibek, Jason Scibek has been invaluable in preparing the PhD, ATC at Duquesne University, has prepared a accompanying PowerPoint presentations. comprehensive and extensively illustrated Power- Point presentation to accompany this text for use When assembling a group of contributors for a in classroom discussion. The PowerPoint presenta- project such as this, it is essential to select individu- tion may also be converted to outlines and given als who are both knowledgeable and well-respected to students as a handout. You can easily download in their fields. It also helps if you can count them the PowerPoint presentation from the McGraw-Hill as friends, and I want to let them know that I hold website at www.mhhe.com. Adopters of the text each of them in the highest regard, both personally can obtain the log in and password to access this and professionally. presentation by contacting your local McGraw-Hill sales representative. The following individuals have invested a great amount of time and effort in reviewing this manu- Test Bank. Each chapter contains true–false, script. Their contributions are present throughout multiple choice, and completion test questions. the text. I would like to thank each one of them for all their valuable insight. Laboratory Manual. The Laboratory Manual to Accompany Therapeutic Modalities for Sports Medicine Gretchen D. Oliver University of Arkansas and Athletic Training will be available for download. Kimberly S. Peer Kent State University Brian Coulombe Texas Lutheran University eSims Brendon P. McDermott University of Connecticut Amanda K. Andrews Troy University eSims is an online assessment tool that provides stu- dents with computerized simulation tests modeled And finally, I would like to thank my wife Tena on the Athletic Training Certification Exam. Using and my sons Brian and Zachary for being under- eSims, students can test and apply their knowledge standing, patient, and supportive while I pursue a and receive instant feedback to their responses. career and a life that I truly enjoy. Developed with input from instructros across the country, eSims prepares students for success in William E. Prentice, their athletic training careers. Chapel Hill, North Carolina

Contributors Gerald W. Bell, Ed.D., A.T.C., P.T. Daniel N. Hooker, Ph.D., P.T., Sc.S, Emeritus Professor of Kinesiology, Community A.T.C. Health and Rehabilitation Associate Director of Sports Medicine College of Allied Health Sciences Campus Health Service University of Illinois at Champaign-Urbana The University of North Carolina Chapel Hill, North Carolina Bob Blake, Ph.D., LMT Assistant Professor William E. Prentice, Ph.D., P.T., Chair, Chemical Education A.T.C. Department of Chemistry and Biochemistry Professor, Coordinator of the Sports Medicine Texas Tech University Specialization Lubbock, Texas Department of Exercise and Sport Science The University of North Carolina Craig Denegar, Ph.D., P.T., A.T.C. Chapel Hill, North Carolina Professor and Department Head in Physical Therapy William S. Quillen, Ph.D., P.T., SCS Neag School of Education Professor and Director University of Connecticut School of Physical Therapy Stoors, Connecticut University of South Florida College of Medicine David O. Draper, Ed.D., A.T.C. Tampa, Florida Professor of Sports Medicine/Athletic Training Department of Exercise Sciences Jason Scibek, Ph.D., A.T.C. College of Health and Human Performance Assistant Professor Brigham Young University Department of Athletic Training Provo, Utah Rangos School of Health Sciences Duquesne University Phillip B. Donley, M.S., P.T., A.T.C. Pittsburgh, Pennsylvania Director Chester County Orthopaedic and Sports Physical xv Therapy West Chester, Pennsylvania

xvi Contributors Frank Underwood, Ph.D., M.P.T., ECS Ethan N. Saliba, Ph.D., P.T., A.T.C. Associate Professor Head Athletic Trainer, Assistant Athletics Director Department of Physical Therapy for Sports Medicine, Department of Athletics University of Evansville Assistant Professor, Department of Kinesiology Clinical Electrophysiologist Adjunct Assistant Professor, Department of Rehabilitation Service Physical Medicine and Rehabilitation Orthopaedic Associates, Inc. University of Virginia Evansville, Indiana Charlottesville, Virginia Susan Foreman-Saliba, Ph.D., M.P.T., A.T.C. Assistant Professor, Sports Medicine and Athletic Training Advisor and Director, Department of Kinesiology Assistant Professor, Department of Physical Medicine and Rehabilitation Assistant Professor, Department of Orthopedic Surgery University of Virginia Charlottesville, Virginia

PART ONE Foundations of Therapeutic Modalities 1 The Basic Science of Therapeutic Modalities 2 Using Therapeutic Modalities to Affect the Healing Process 3 Managing Pain with Therapeutic Modalities

1C H A P T E R The Basic Science of Therapeutic Modalities William E. Prentice and Bob Blake F or the athletic trainer who chooses to incor- porate a therapeutic modality into his or her Following completion of this chapter, clinical practice, some knowledge and under- the athletic trainer student will be able to: standing of the basic science behind the use of these • List and describe the different forms of energy agents is useful.9 The interactions between energy and matter are fascinating, and they are the physi- used with therapeutic modalities. cal basis for the various therapeutic modalities that are described in this book. This chapter will describe • Classify the various modalities according to the the different forms of energy, the ways energy can type of energy utilized by each. be transferred, and how energy transfer affects bio- logic tissues. A strong theoretical knowledge base • Analyze the relationship between wavelength can help clinicians understand how each therapeu- and frequency for electromagnetic energy. tic modality works. • Discuss the electromagnetic spectrum and how FORMS OF ENERGY various modalities that use electromagnetic energy are related. Energy is defined as the capacity of a system for doing work and exists in various forms. Energy is • Explain how the laws governing the effects of not ordinarily created or destroyed, but it is often electromagnetic energy apply to diathermy, transformed from one form to another or trans- laser, and ultraviolet light. ferred from one location to another.15 • Discuss how the thermal energy modalities, There is considerable confusion among even thermotherapy and cryotherapy, transfer heat the most experienced athletic trainers regarding the through conduction. different forms of energy involved with the various therapeutic modalities. The forms of energy that • Explain the various ways electrical energy can are relevant to the use of therapeutic modalities be used to produce a therapeutic effect. are electromagnetic energy, thermal energy, electri- cal energy, sound energy, and mechanical energy.15 • Compare and contrast the properties of Shortwave and microwave diathermy, infrared electromagnetic and sound energy. lamps, ultraviolet light therapy, and low-power la- sers utilize electromagnetic energy. Thermotherapy • Explain how intermittent compression, traction, and massage use mechanical energy to produce a therapeutic effect. energy The capacity of a system for doing work. 2

CHAPTER 1 The Basic Science of Therapeutic Modalities 3 and cryotherapy transfer thermal energy. The elec- through which the sound waves travel. Although trical stimulating currents, iontophoresis and bio- the electrical, electromagnetic, and sound energy feedback, utilize electrical energy. Ultrasound and treatments all heat tissues, the physical mechanism extracorporal shockwave therapy utilize sound en- of action for each is different. ergy. Intermittent compression, traction, and mas- sage utilize mechanical energy (Table 1–1). The mechanism of action of each therapeu- tic modality depends on which form of energy is Each of these therapeutic agents transfers en- utilized during its application. Different forms of ergy in one form or another into or out of biologic energy are generated and transferred by differ- tissues. Different forms of energy can produce simi- ent mechanisms. Electromagnetic energy is typi- lar effects in biologic tissues. For example, tissue cally generated by a high energy source and is heating is a common effect of several treatments transmitted by the movement of photons. Thermal that utilize different types of energy. Electrical cur- energy can be transferred by conduction, which rents that pass through tissues will generate heat involves the flow of thermal energy between ob- as a result of the resistance of the tissue to the pas- jects that are in contact with each other. Electrical sage of electricity. Electromagnetic energy such energy is stored in electric fields and delivered by as light waves will heat any tissues that absorb the movement of charged particles. Acoustic vibra- it. Ultrasound treatments will also warm tissues tions produce sound waves that can pass through a medium. Each form of energy and the mechanism TABLE 1–1 of its transfer will be discussed in more detail to provide the scientific basis for understanding the ELECTROMAGNETIC ENERGY MODALITIES therapeutic modalities.10 • Shortwave diathermy ELECTROMAGNETIC ENERGY • Microwave diathermy • Infrared lamps Radiation is a process by which electromagnetic • Ultraviolet therapy energy travels from its source outward through • Low-power laser space.14 Sunlight is a visible type of radiant en- ergy, and we know that it not only makes objects THERMAL ENERGY MODALITIES visible but also produces heat. The sun emits a spectrum of visible and invisible massless radi- • Thermotherapy ant energy and ejects high energy particles as • Cryotherapy a result of high-intensity chemical and nuclear reactions. The massless radiant energy emissions ELECTRICAL ENERGY MODALITIES from the sun are called photons. A photon is the energy carrier that composes all electromagnetic • Electrical stimulating currents radiation. Photons travel as waves at the speed • Biofeedback of light, approximately 300 million meters per • Iontophoresis radiation (1) The process of emitting energy from SOUND ENERGY MODALITIES some source in the form of waves. (2) A method of heat transfer through which heat can be either gained • Ultrasound or lost. • Extracorporal shockwave therapy photon The energy carrier that composes all elec- MECHANICAL ENERGY MODALITIES tromagnetic radiation. • Intermittent compression • Traction • Massage

4 PART ONE Foundations of Therapeutic Modalities Analogy 1–1 second. Since photons all travel at the same speed, The relationship between velocity, wavelength, and they are distinguished by their wave properties of frequency is similar to that of a 7-foot tall basketball wavelength and frequency, as well as the amount player and a 5-foot tall gymnast who are asked to run of energy carried by each photon. a 50-meter race and finish at the same time. Because his legs are longer, the basketball player will take lon- The Relationship between Wavelength ger strides (wavelength) but fewer steps (frequency) and Frequency to get to the finish line. Conversely, the gymnast has a short stride length (wavelength) and therefore must Wavelength is defined as the distance between the take more steps (frequency) if she is to travel an equal peak of one wave and the peak of either the pre- distance in the same time as the basketball player. ceding or succeeding wave. Frequency is defined Thus, since velocity is a constant, there is an inverse as the number of wave oscillations or vibrations relationship between wavelength and frequency. occurring in a particular time unit and is com- monly expressed in Hertz (Hz). One Hertz is one dealing with electromagnetic energy of any kind, vibration per second (Figure 1–1). we can use the speed of light, 3.0 × 108 m/s in that equation. That speed is not appropriate for electrical Since all forms of electromagnetic radiation energy waves or sound energy waves, which do not travel at a constant velocity through space, photons travel at the speed of light.11 with longer wavelengths have lower frequencies and photons with shorter wavelengths have higher The other equation that is important with elec- frequencies.12 The following equation is useful for tromagnetic radiation is the energy equation. The doing calculations involving the speed, wavelength, energy of a photon is directly proportional to its fre- and frequency of waves. quency. This means that the electromagnetic radia- tion with higher frequency also has higher energy. speed = wavelength ë frequency We will relate this to the effects that each form of c=këv electromagnetic radiation can produce in tissues. An inverse or reciprocal relationship exists between E=hëv wavelength and frequency. The longer the wave- length of a wave is, the lower the frequency of the (The letter h is known as Planck’s constant and has a wave has to be. The velocity of electromagnetic value of 6.626 × 10-34 Js. When Planck’s constant radiation is a constant, 3 × 108 m/sec. If we know is multiplied by a frequency in vibrations per sec- the wavelength of any wave, the frequency of that ond, the result has the standard scientific energy wave can also be calculated. Whenever we are unit of Joules.) Wavelength The Electromagnetic Energy Spectrum If a ray of sunlight is passed through a prism, it will be broken down into various colors in a predictable rainbow-like pattern of red, orange, yellow, green, Time wavelength The distance from one point in a prop- Figure 1–1 Wavelength and frequency. agating wave to the same point in the next wave. frequency The number of cycles or pulses per second.

CHAPTER 1 The Basic Science of Therapeutic Modalities 5 Infrared radiation from the sun, called ultraviolet radia- tion. Infrared radiation is lower in energy than Red red light (infra means lower or below). Ultraviolet radiation is higher in energy than violet light (ultra Orange means greater or above). Almost all of the electro- magnetic radiation produced by the sun is invis- Yellow ible. The entire electromagnetic spectrum includes radio and television waves, diathermies, infrared Green rays, visible light rays, ultraviolet rays, x-rays, and gamma rays (Table 1–2). Blue The electromagnetic spectrum places all of Red violet the electromagnetic modalities in order based on wavelengths and corresponding frequencies. It is Ultraviolet apparent, for example, that the shortwave diather- mies have the longest wavelength and the lowest Figure 1–2 When a beam of light is shone through a frequency and, all other factors being equal, there- prism, the various electromagnetic radiations in visible fore should have the greatest depth of penetration. light are refracted and appear as a distinct band of color As we move down the chart, the wavelengths in called a spectrum. each region become progressively shorter and the frequencies progressively higher. Diathermy, the blue, indigo, and violet (Figure 1–2). The range of various sources of infrared heating, and the ul- colors is called a spectrum. The colors that we can traviolet regions have progressively less depth of detect with our eyes are referred to as visible light penetration.4 or luminous radiations. Each of these colors repre- sents a photon of a different energy. They appear as Note that the regions labeled as radio and television different colors because the various forms of radi- frequencies, visible light, and high-frequency ionizing ant energy are refracted or change direction as a and penetrating radiations certainly fall under the clas- result of differences in wavelength and frequency sification of electromagnetic radiations. However, they of each color. When passed through a prism, the do not have application as therapeutic modalities and, type of radiant energy refracted the least appears although extremely important to our everyday way of as the color red, whereas that refracted the most is life, warrant no further consideration in the context of violet.11 The longest wavelength light is red in color this discussion. and low in energy whereas the shortest wavelength light is violet and relatively higher in energy. spectrum Range of visible light colors. This beam of electromagnetic radiation from refraction The change in direction of a wave or the sun that passes through the prism also includes radiation wave when it passes from one medium or propagating forms of radiant energy that are not type of tissue to another. visible to our eyes.15 If a thermometer is placed close to the red end of the visible light spectrum, the infrared radiation The portion of the electro- thermometer will rise in temperature. This is be- magnetic spectrum associated with thermal changes cause there is invisible radiation with longer wave- located adjacent to the red portion of the visible light lengths than red light, called infrared radiation, spectrum. which is absorbed by the thermometer. When the infrared radiation is absorbed by the thermometer, ultraviolet radiation The portion of the electro- it heats the thermometer, just like the light from magnetic spectrum associated with chemical changes the sun can warm your skin as your skin absorbs located adjacent to the violet portion of the visible the light. Likewise, photographic film that is placed light spectrum. close to the violet end of the visible light spectrum can be developed by another form of invisible

6 PART ONE Foundations of Therapeutic Modalities TABLE 1–2 Electromagnetic Energy Spectrum* ESTIMATED CLINICALLY CLINICALLY EFFECTIVE USED USED DEPTH OF PHYSIOLOGIC REGION WAVELENGTH FREQUENCY** PENETRATION EFFECTS Commercial Rradio 22 m 13.56 MHz 3 cm Deep tissue temperature and Television 11 m 27.12 MHz 5 cm increase, vasodilation, Frequencies‡ increased blood flow 433.9 MHz Shortwave 915 MHz Deep tissue temperature diathermy 2450 MHz increase, vasodilation, increased blood flow Microwave 69 cm 1.04 × 1013 Hz diathermy 33 cm 2.08 × 1013 Hz Superficial temperature 12 cm increase Infrared Luminous IR (1341° F) 28,860 Å Vasodilation— Nonluminous IR 14,430 Å increased blood flow (3140° F) Pain modulation and Visible light wound healing Red Laser Superficial chemical changes GaAs 9100 Å 3.3 × 1013 Hz 5 cm 4.74 × 1013 Hz 10 –15 mm Tanning effcts HeNe 6328 Å Bactericidal Violet Ultraviolet UV-A 3200–4000 Å 9.38 × 1013–7.5 × 1013 Hz 1.03 × 1014–9.38 × 1013 Hz UV-B 2900–3200 Å 1.50 × 1014–1.03 × 1014 Hz 1 mm UV-C 2000–2900 Å Ionizing radiation (x-ray, gamma rays, cosmic rays)‡ *The only forms of electromagnetic energy included are the ones that obey the equations C = k × v and E = h × v. Neither electrial currents nor heat traveling by conduction travels at the speed of light. **Calculated using C = λ × F, C = velocity (3 × 10 m/sec), λ = wavelength, F = frequency. ‡Although these fall under the classification of electromagnetic energy, they have nothing to do with therapeutic modalities and thus warrant no further discussion in this text. How Is Electromagnetic Energy have been produced by heating objects such as a Produced? thin filament to very high temperatures. Objects are composed of atoms, which in turn are com- Various forms of electromagnetic radiation can be posed of positively charged nuclei surrounded by used by athletic trainers to treat patients provided negatively charged electrons. As the temperature that these forms of energy can be produced and increases in a particular substance, the charged directed in safe and economical ways. Tradition- subatomic particles within the substance vibrate ally, ultraviolet, infrared, and visible light rays more rapidly due to the increase in available

CHAPTER 1 The Basic Science of Therapeutic Modalities 7 energy. The rapid movement of any charged par- energy to damage tissues. As this radiation is ticles, such as the negatively charged electrons not very penetrating, the result of exposure to within atoms, produces electromagnetic waves. At ultraviolet radiation is the superficial skin damage higher temperatures, the number of electromag- that we call sunburn. netic waves produced and the average frequency of those waves increase. This is how incandescent Laws Governing the Effects of light bulbs in our homes work. The electrical energy Electromagnetic Energy heats the filaments to very high temperatures, which causes them to emit radiation. The electro- When electromagnetic radiation strikes or comes magnetic waves produced by heated filaments in- in contact with various objects, it can be reflected, clude a broad range of radiation and require large transmitted, refracted, or absorbed, depending on amounts of energy to produce. As technology has the type of radiation and the nature of the object improved, more specific and economical ways it interacts with.2 The rays that rebound off the to produce electromagnetic radiation have been material are said to be reflected. If a ray passes developed for use in the therapeutic modalities. from one material to another, it changes its path Electronic tubes or transistors can convert electri- by a process called refraction. Rays passing through cal energy into radio waves and a device called a a material are said to be transmitted through magnetron can produce focused bursts of micro- the material. A portion of the radiation may be wave radiation. absorbed by the material. Any photons that are not absorbed by the tissue will be transmitted to Effects of Electromagnetic Radiations deeper layers. The intensity of a ray depends on how many photons compose the ray (Figure 1–3). The effects of electromagnetic radiation on tissues Generally, the radiation used in the therapeutic depend on the wavelength, frequency, and energy modalities that has the longest wavelength tends of the electromagnetic waves that penetrate those to also have the greatest depths of penetration. It tissues. Of the forms of electromagnetic energy used by the therapist or trainer, those with Analogy 1–2 longer wavelengths are the most penetrating. At the low energy end of the electromagnetic The colors of a rainbow are created when sunlight spectrum, characterized by low frequency and long (electromagnetic energy) is refracted through water wavelength radiation, the basic effect is to heat droplets. The different colors appear because of vary- tissues. The electromagnetic radiation with higher ing wavelengths and frequencies, which are refracted amounts of energy per photon can have different, differently. more dramatic effects on tissues. The large regions of radiation with longer wavelengths than infrared diathermy The application of high-frequency elec- radiations are known as the diathermies. These trical energy used to generate heat in body tissue as include shortwave and microwave radiations. a result of the resistance of the tissue to the passage of They penetrate tissues more deeply than infrared energy. or visible light. Infrared radiations, such as those produced by luminous and nonluminous reflection The bending back of light or sound infrared lamps, and visible light also heat tissues. waves from a surface that they strike. These types of radiation are less penetrating than microwave radiation, so the warming effects are transmission The propagation of energy through a more superficial. Ultraviolet radiation is more particular biologic tissue into deeper tissues. energetic than visible light and carries enough absorption Energy that stimulates a particular tissue to perform its normal function.

8 PART ONE Foundations of Therapeutic Modalities Electromagnetic energy that too much energy absorbed in a given period of time may seriously impair normal function and, 1. Reflected if severe enough, may cause irreparable damage.5 Skin Law of Grotthus-Draper. The inverse rela- tionship that exists between energy absorption by 2. Refracted Fat a tissue and energy penetration to deeper layers is described by the Law of Grotthus-Draper. That 3. Absorbed Muscle portion of the electromagnetic energy that is not reflected will penetrate into the tissues (skin lay- Figure 1–3 When electromagnetic radiations contact ers), and some of it will be absorbed superficially. human tissues, they may be reflected, refracted, or If too much radiation is absorbed by superficial absorbed. Energy that is transmitted through the tissues tissues, not enough will be absorbed by the deeper must be absorbed before any physiologic changes can tissues to stimulate the tissues. If the amount of take place. energy absorbed is sufficient to stimulate the target tissue, some physiologic response will occur.2,5 If must be added, however, that a number of other the target tissue is a motor nerve and your treat- factors, which are discussed later, can also contrib- ment goal is to cause a depolarization of that ute to the depth of penetration. motor nerve, then enough energy must be ab- sorbed by that nerve to cause the desired depo- Arndt-Schultz Principle. The purpose larization. An example showing application of of using therapeutic modalities is to stimulate the Law of Grotthus-Draper is the use of ultra- body tissue. This stimulation will only occur if sound treatment to increase tissue temperature in energy produced is absorbed by the tissue.2,5 The the deeper portions of the gluteus maximus mus- Arndt-Schultz principle states that no reac- cle. An athletic trainer could use ultrasound at a tions or changes can occur in the body tissues frequency of either 1 MHz (long wavelength) or if the amount of energy absorbed is insufficient 3 MHz (short wavelength). Using ultrasound treat- to stimulate the absorbing tissues. The goal of ment at a frequency of 1 MHz would be more the athletic trainer should be to deliver sufficient effective at penetrating the deeper tissues than energy to stimulate the tissues to perform their ultrasound treatment at 3 MHz, since less energy normal function. An example would be using an would be absorbed superficially for the longer electrical stimulating current to create a muscle wavelength. contraction. To achieve the depolarization of a motor nerve, the intensity of the current must be Cosine Law. Any reflection of electromag- increased until enough energy is made available netic radiation or other waves will reduce the and is absorbed by that nerve to facilitate a depo- amount of energy that is available for therapeutic larization. The athletic trainer should also realize purposes. The smaller the angle between the prop- agating ray and the right angle, the less radiation reflected and the greater the absorption. Thus, Analogy 1–3 Arndt-Schultz principle No reactions or changes can occur in the body if the amount of energy When you go to the beach and are lying in the sun, absorbed is not sufficient to stimulate the absorbing you are more likely to get sunburned during the mid- tissues. dle of the day when the sun’s rays are striking your skin at closer to a right angle than later in the after- Law of Grotthus-Draper Energy not absorbed by noon when sunlight is at more of an oblique angle. the tissues must be transmitted.

CHAPTER 1 The Basic Science of Therapeutic Modalities 9 radiant energy is more easily transmitted to deeper takes, the physiologic effects are apparent only tissues if the source of radiation is at a right angle when the energy is absorbed by a specific tissue. to the area being radiated. This principle, known Treatments will only be effective if enough en- as the cosine law, is extremely important in the ergy is absorbed by the tissues, so modalities are chapters dealing with the diathermies, ultraviolet most effective when placed as close to the body as light, and infrared heating, since the effectiveness possible. of these modalities is based to a large extent on how they are positioned with regard to the patient Electromagnetic Energy Modalities (Figure 1–4).5 An example showing the applica- tion of the cosine law could be that, when doing Diathermy. The diathermies are considered an ultrasound treatment, the surface of the appli- to be high-frequency modalities because they use cator should be kept as flat on the skin surface as radiation with more than 1 million cycles per sec- possible. This allows the acoustic energy coming ond. When impulses of such a short duration come from the applicator to strike the surface as close in contact with human tissue, there is not sufficient to 90 degrees as possible, thus minimizing the time for ion movement to take place. Consequently, amount of energy reflected. there is no stimulation of either motor or sensory nerves. The energy of this rapidly vibrating radia- Inverse Square Law. The intensity of the tion produces heat as it is absorbed by tissue cells, radiation striking a particular surface is known to resulting in a temperature increase.6 Shortwave vary inversely with the square of the distance from diathermy may be either continuous or pulsed. the source.3 For example, when using an infrared Both continuous shortwave as well as microwave heating lamp to heat the low back region, the diathermy are used primarily for their thermal intensity of heat energy at the skin surface with effects, whereas pulsed shortwave is used for its the lamp positioned at a distance of 10 inches will nonthermal effects.1,5 Diathermy is discussed in be four times greater than if the lamp is placed at more detail in Chapter 10. a 20-inch distance. This principle, known as the inverse square law, obviously is of great con- Low-Power Laser. The word LASER is an sequence when setting up a specific modality to acronym for light amplification by stimulated emission achieve a desired physiologic effect (Figure 1–5). of radiation and applies to any instrument that gen- Regardless of the path this transmitted energy erates light using that technique. There are lasers that produce light in either the infrared or visible Energy source Energy source light portions of the spectrum. Lasers can be constructed to operate at certain power levels. High-power lasers are used in surgery for purposes of incision, coagulation of vessels, and thermolysis, owing to their thermal effects. The low-power or cold laser produces little or no thermal effects but seems to have some significant (a) (b) cosine law Optimal radiation occurs when the source of radiation is at right angles to the center of Figure 1–4 The cosine law states that the smaller the the area being radiated. angle between the propagating ray and the right angle, the less radiation reflected and the greater absorbed. inverse square law The intensity of radiation Thus the energy absorbed in a would be greater than in b. striking a particular surface varies inversely with the square of the distance from the radiating source.

10 PART ONE Foundations of Therapeutic Modalities I I Figure 1–5 The inverse square law states that the intensity of the radiation striking a particular surface varies inversely with the square of the distance from the source. clinical effect on soft-tissue and fracture healing, as THERMAL ENERGY well as on pain management, through stimulation of acupuncture and trigger points. The laser as a Earlier it was stated that any object heated (or therapeutic tool is discussed in Chapter 9. cooled) to a temperature different than the sur- rounding environment will dissipate (or absorb) Ultraviolet Light. The ultraviolet portion of heat through conduction to (or from) the other ma- the electromagnetic spectrum is higher in energy terials with which it comes in contact. than violet light. As stated previously, the radia- tion in the ultraviolet region is undetectable by the There is confusion over the relationship be- human eye. However, if a photographic plate is tween electromagnetic energy and thermal energy placed at the ultraviolet end, chemical changes will transfer associated with hot and cold packs. It is cor- be apparent. Although an extremely hot source rect to think of the infrared modalities as being those (7000–9000° C) is required to produce ultraviolet modalities whose primary mechanism of action is wavelengths, the physiologic effects of ultraviolet the emission of infrared radiation for the purpose of are mainly chemical in nature and occur entirely in increasing tissue temperatures.8 All warm objects, the cutaneous layers of skin. The maximum depth including whirlpool baths, emit infrared radiation, of penetration with ultraviolet is about 1 mm. but the amount of infrared energy that is radiated from hot and cold baths is very small compared Due to the availability of oral and topical medi- to the amount that transfers to and from them by cations to treat skin lesions, ultraviolet therapy is conduction. Modalities such as hot and cold packs no longer used as a treatment modality by athletic operate by conduction of thermal energy, so they trainers and thus will not be discussed further in are better described as conductive modalities. The this text.

CHAPTER 1 The Basic Science of Therapeutic Modalities 11 conductive modalities are used to produce a local The modalities classified as thermotherapy modali- and occasionally a generalized heating or cooling ties include warm whirlpool, warm hydrocollator of the superficial tissues with a maximum depth of packs, paraffin baths, and fluidotherapy. The spe- penetration of 1 cm or less. Conductive modalities cific procedures for applying these techniques are are generally classified into those that produce a discussed in detail in Chapter 4. tissue temperature increase, which we refer to as thermotherapy, and those that produce a tissue Cryotherapy. Cryotherapy techniques are temperature decrease, which we call cryotherapy. used primarily to produce a tissue temperature decrease for a variety of therapeutic purposes. The Earlier we stated that visible light, luminous modalities classified as cryotherapy modalities in- infrared, and nonluminous infrared lamps are clas- clude ice massage, cold hydrocollator packs, cold sified as electromagnetic energy modalities. This whirlpool, cold spray, contrast baths, ice immer- is because their mechanism of energy transfer is sion, cryo-cuff, and cryokinetics. The specific proce- through electromagnetic radiation, not conduction. dures for applying these techniques are discussed in detail in Chapter 4. The rate of heat transfer from one object to an- other is proportional to the difference in temperature ELECTRICAL ENERGY between them. If two objects are very close in tem- perature, the transfer of heat will be slow. If there is In general, electricity is a form of energy that can a great temperature difference between two objects, effect chemical and thermal changes on tissue. the heat transfer between them will be very rapid. Electrical energy is associated with the flow of elec- This has important consequences for the use of hot trons or other charged particles through an electric baths and cold baths. When a cold pack (8° F) is field. Electrons are particles of matter that have a placed in contact with skin (98.6° F), the difference negative electrical charge and revolve around the in temperature is approximately 90° F, so the heat core, or nucleus, of an atom. An electrical current flow from the skin to the cold pack is very rapid. This refers to the flow of charged particles that pass will cool the skin very rapidly and to a greater tissue along a conductor such as a nerve or wire. Electro- depth. When tissues are placed in a hot whirlpool therapeutic devices generate current, which, when (110° F), the difference in temperature is only about introduced into biological tissue, are capable of 10° F, so the heat transfer from the bath to the skin producing specific physiological changes. is much slower. Whirlpools also have other effects, such as the prevention of evaporative cooling of the An electrical current applied to nerve tis- skin, but the general principle that cold packs work sue at a sufficient intensity and duration to reach more rapidly and to a greater tissue depth holds true. that tissue’s excitability threshold will result in a membrane depolarization or firing of that nerve. It should be added that in addition to produc- Electrical stimulating currents affect nerve and ing a tissue temperature increase or decrease, the muscle tissue in various ways, based on the action thermal modalities can elicit either increases or de- creases in circulation depending on whether heat or Clinical Decision-Making Exercise 1–1 cold is used. They are also known to have analgesic effects as a result of stimulation of sensory cutane- ous nerve endings. Thermal Energy Modalities Several modalities can be used to manage pain. Of the modalities discussed, which may be used Thermotherapy. Thermotherapy techniques to modulate pain and which should an athletic are used primarily to produce a tissue tempera- trainer recommend as the best to use immediately ture increase for a variety of therapeutic purposes. following injury?

12 PART ONE Foundations of Therapeutic Modalities of electricity on tissues. Any electrical currents that different. Acoustical waves travel at the speed of pass through tissues will warm the tissues based on sound. Electromagnetic waves travel at the speed the resistance of the tissues to the flow of electricity. of light. Since sound travels more slowly than light, The clinically used frequencies of electrical currents wavelengths are considerably shorter for acoustic range from 1 Hz to 4000 Hz. Most stimulators have vibrations than for electromagnetic radiations at the flexibility to alter the treatment parameters of any given frequency.5 For example, ultrasound the device to elicit a desired physiologic response in traveling in the atmosphere has a wavelength of addition to the warming of tissues.10 approximately 0.3 mm, whereas electromagnetic radiations would have a wavelength of 297 m at a Electrical Energy Modalities similar frequency. Electrical Stimulating Currents. The nerve Electromagnetic radiations are capable of trav- and muscle stimulating currents are capable of eling through space or a vacuum. As the density of (1) modulating pain through stimulation of cutane- the transmitting medium is increased, the velocity ous sensory nerves at high frequencies; (2) producing of electromagnetic radiation decreases very slightly. muscle contraction and relaxation or tetany, depend- Acoustic vibrations (sound) will not be transmit- ing on the type of current and frequency; (3) facilitat- ted at all through a vacuum since they propagate ing soft-tissue and bone healing through the use of through molecular collisions. The more rigid the subsensory microcurrents low-intensity stimulators; transmitting medium is, the greater the velocity of and (4) producing a net movement of ions through sound will be. Sound has a much greater velocity the use of continuous direct current and thus elicit- of transmission in bone tissue (3500 m/sec), for ing a chemical change in the tissues, which is called example, than in fat tissue (1500 m/sec). iontophoresis (see Chapter 6).14 The electrical stimu- lating currents and their various physiologic effects Sound Energy Modalities are discussed in detail in Chapter 5. Ultrasound. A therapeutic modality athletic Electromyographic Biofeedback. Electro- trainers frequently use is ultrasound. Ultrasound is myographic biofeedback is a therapeutic procedure the same form of energy as audible sound, except that uses electronic or electromechanical instru- that the human ear cannot detect ultrasound fre- ments to accurately measure, process, and feed back quencies. Frequencies of ultrasound wave produc- reinforcing information via auditory or visual sig- tion are between 700,000 and 1 million cycles per nals. Clinically, it is used to help the patient develop second. Frequencies up to around 20,000 Hz are greater voluntary control in terms of either neuro- detectable by the human ear. Thus the ultrasound muscular relaxation or muscle reeducation follow- portion of the acoustic spectrum is inaudible. Ultra- ing injury. Biofeedback is discussed in Chapter 7. sound is frequently classified along with the elec- tromagnetic modalities, shortwave and microwave SOUND ENERGY diathermy, as a deep-heating, “conversion”-type modality, and it is certainly true that all of these Acoustic energy and electromagnetic energy have are capable of producing a temperature increase in very different physical characteristics. Sound en- human tissue to a considerable depth. However, ul- ergy consists of pressure waves due to the mechani- trasound is a mechanical vibration, a sound wave, cal vibration of particles, whereas electromagnetic produced and transformed from high-frequency radiation is carried by photons. The relationship electrical energy.5 between velocity, wavelength, and frequency is the same for sound energy and electromagnetic Ultrasound generators are generally set at a energy, but the speeds of the two types of waves are standard frequency of 1–3 MHz (1000 kHz). The depth of penetration with ultrasound is much

CHAPTER 1 The Basic Science of Therapeutic Modalities 13 Clinical Decision-Making Exercise 1–2 MECHANICAL ENERGY The athletic trainer is treating a patient with a In all instances in which work is done, there is chronic low back strain. At this point it has been an object that supplies the force to do the work. decided that heating the area is the treatment of When work is done on the object, that object gains choice. Which of the modalities discussed briefly energy. The energy acquired by the objects upon in this chapter may be used as heating modalities? which work is done is known as mechanical en- Which of these modalities would you choose to ergy.15 Mechanical energy is the energy possessed provide the greatest depth of penetration? by an object due to its motion or due to its position. Mechanical energy can be either kinetic energy greater than with any of the electromagnetic radia- (energy of motion) or potential energy (stored tions. At a frequency of 1 MHz, 50% of the energy energy of position). Objects have kinetic energy if produced will penetrate to a depth of about 5 cm. they are in motion. Potential energy is stored by The reason for this great depth of penetration is that an object and has the potential to be created when ultrasound travels very well through homogeneous that objected is stretched or bent or squeezed. The tissue (e.g., fat tissue), whereas electromagnetic kinetic energy created by a clinician’s hands moves radiations are almost entirely absorbed. Thus when to apply a force that can stretch, bend, or com- therapeutic penetration to deeper tissues is desired, press skin, muscles, ligaments, and the like. The ultrasound is the modality of choice.7,10 stretched, bent, or compressed structure possesses potential energy that can be released when the Therapeutic ultrasound traditionally has been force is removed. used to produce a tissue temperature increase through thermal physiologic effects. However, it is Mechanical Energy Modalities also capable of enhancing healing at the cellular level as a result of its nonthermal physiologic ef- Intermittent compression, traction techniques, fects. The clinical usefulness of therapeutic ultra- and massage each use mechanical energy involv- sound is discussed in greater detail in Chapter 8. ing a force applied to some soft-tissue structure to create a therapeutic effect. These mechanical Extracorporeal Shock Wave Therapy energy modalities are discussed in Chapters 11, (ESWT). Extracorporeal shock wave therapy (ESWT) 12, and 13. is a relatively new noninvasive modality used in the treatment of both soft-tissue and bone injuries. The Clinical Decision-Making Exercise 1–3 shock waves, in contrast to the connotation of an electrical shock, are actually pulsed high-pressure, With which of the modalities described briefly in short-duration (<1 m/sec) sound waves. This this chapter are the cosine law and the inverse sound energy is concentrated in a small focal area square law of greatest consideration? (2–8 mm in diameter) and is transmitted through a coupling medium to a target region with little at- mechanical energy Energy acquired by the objects tenuation. Over the last several years, a number of upon which work is done. investigators have used this modality successfully kinetic energy Energy of motion. in treating plantar fasciitis, medial/lateral epicon- potential energy Stored energy of position. dylitis, and nonunion fractures. However, at this point the expense of using ESWT equipment is pro- hibitive, and few clinicians have access to this de- veloping modality. Thus ESWT will not be discussed further in this text.

14 PART ONE Foundations of Therapeutic Modalities Summary 1. The forms of energy that are relevant to the 7. Modalities that utilize electrical energy can use of therapeutic modalities are electromag- (1) cause pain modulation through stimula- netic energy, thermal energy, electrical energy, tion of cutaneous sensory nerves; (2) pro- sound energy, and mechanical energy. duce muscle contraction and relaxation or tetany, depending on the type of current and 2. The various forms of energy may be reflected, frequency; (3) facilitate soft-tissue and bone refracted, absorbed, or transmitted in the healing through the use of subsensory micro- tissues. currents; and (4) produce a net movement of ions thus eliciting a chemical change in the 3. All forms of electromagnetic energy travel at tissues. the same velocity; thus, wavelength and fre- quency are inversely related. 8. Acoustic energy and electromagnetic energy have very different physical characteristics. 4. The electromagnetic spectrum places all of the electromagnetic energy modalities including 9. Mechanical energy can be either kinetic energy diathermy, laser, ultraviolet light, and lumi- (energy of motion) or potential energy (stored nous infrared lamps in order based on wave- energy of position). The kinetic energy cre- lengths and corresponding frequencies. ated by a clinician’s hands moves to apply a force that can stretch, bend, or compress skin, 5. The Arndt-Schultz principle, the Law of Grot- muscles, ligaments, and the like. The stretched, thus-Draper, the cosine law, and the inverse bent, or compressed structure possesses poten- square law can each be applied to the electro- tial energy that can be released when the force magnetic energy modalities. is removed. 6. Thermotherapy and cryotherapy modalities transfer thermal energy from a heating or cool- ing source to the body through conduction. Review Questions 1. What are the various forms of energy 8. Explain the cosine and inverse square laws produced by therapeutic modalities? relative to tissue penetration of electromag- netic energy. 2. What is radiant energy and how is it produced? 9. How do the thermal energy modalities trans- fer energy? 3. What is the relationship between wavelength and frequency? 10. What physiologic changes can the use of elec- trical energy produce in human tissue? 4. What are the characteristics of electromag- netic energy? 11. Which of the therapeutic modalities produce sound energy? 5. Which of the therapeutic modalities produce electromagnetic energy? 12. What are the differences between electromag- netic energy and sound energy? 6. What is the purpose of using a therapeutic modality? 13. What modalities utilize mechanical energy to produce a therapeutic effect? 7. According to the Law of Grotthus-Draper, what happens to electromagnetic energy when it comes in contact with and/or pen- etrates human biologic tissue?

CHAPTER 1 The Basic Science of Therapeutic Modalities 15 Self-Test Questions True or False 7. According to the cosine law, to minimize re- 1. Wavelength is defined as the number of cycles per second. flection and maximize absorption, the energy 2. To achieve deeper tissue penetration, the wavelength must be increased. source must be at a angle to 3. Continuous shortwave diathermy produces thermal effects. the surface. a. 45 degree b. 90 degree c. 180 degree Multiple Choice d. 0 degree 4. Which of the following is NOT an electromag- 8. Electrical stimulating currents may produce netic energy modality? the following effects: a. Ultraviolet light a. Muscle contraction b. Ultrasound b. Net ion movement c. Low-power laser c. Decrease in pain d. Shortwave diathermy d. All of the above 5. Sound or radiation waves that change direc- 9. Thermal energy modalities generally affect tion when passing from one type of tissue to superficial tissue up to cm deep, another are said to . a. 5 cm a. Transmit b. 0.5 cm b. Absorb c. 1 cm c. Reflect d. 10 cm d. Refract 10. Based on their different characteristics, which 6. The states that if superfi- of the following travels at greater velocity cial tissue does not absorb energy, it must be through human tissue? transmitted deeper. a. Sound energy a. Law of Grotthus-Draper b. Electromagnetic energy b. Cosine law c. Both a and b travel at the same rate. c. Inverse square law d. Neither a nor b travels through human d. Arndt-Schultz principle tissue. Solutions to Clinical Decision-Making Exercises 1–1 Superficial heat and cold, electrical stimulat- or ultrasound—all of which have the ability ing currents, and low-power laser may all be to produce heat in the tissues. Ultrasound effective for modulating pain. However, ice is has a greater depth of penetration than any likely the best choice immediately following of the electromagnetic or thermal modalities injury because it will not only modulate pain since sound energy is more effectively trans- but will also cause vasoconstriction and thus mitted through dense tissue than is electro- help to control swelling. magnetic energy. 1–3 When setting up a patient for treatment using 1–2 The athletic trainer may choose to use infra- either microwave diathermy or ultraviolet red heating modalities, shortwave diathermy,

16 PART ONE Foundations of Therapeutic Modalities therapy, it is critical that the athletic trainer absorbed and not reflected. It is also essential consider the angle at which the electromag- to know the distance that these modalities will netic energy is striking the body surface to be placed from the surface to achieve the right ensure that most of the energy will be amount of energy in the target tissue. References 8. Lehmann, J, editor: Therapeutic heat and cold, ed. 4, Balti- more, 1990, Williams and Wilkins. 1. Blank, M, editor: Electromagnetic fields: biological interactions and mechanisms, Washington, DC, 1995, American Chemi- 9. Nadler, SF: Complications from therapeutic modalities: cal Society. results of a national survey of athletic trainers, Arch Phys Med Rehab 84(6):849–853, 2003. 2. Gasos, J, and Stavroulakis, P: Biological effects of electromag- netic radiation, New York, 2003, Springer-Verlag. 10. Schriber, W: A manual of electrotherapy, Philadelphia, 1975, Lea & Febiger. 3. Goats, GC: Appropriate use of the inverse square law, Phys- iotherapy 74(1):8, 1988. 11. Reitz, J, Milford, F, and Christy, R: Foundations of elec- tromagnetic theory, ed 2, Reading, MA, 1992, Addison 4. Goldman, L: Introduction to modern phototherapy, Spring- Wesley. field, IL, 1978, Charles C Thomas. 12. Smith, G: Introduction to classical electromagnetic radiation, 5. Griffin, J, and Karselis, T: Physical agents for physical athletic Boston, 1997, Cambridge University Press. trainers, Springfield, IL, 1978, Charles C Thomas. 13. Stillwell, K: Therapeutic electricity and ultraviolet radiation, 6. Hitchcock, RT, and Patterson, RM: Radio-frequency and ELF Baltimore, 1983, Williams & Wilkins. electromagnetic energies: a handbook for healthcare profession- als, New York, 1995, Van Nostrand Reinhold. 14. Venes, D, and Thomas, CL: Taber’s cyclopedic medical dictionary, Philadelphia, 2005, F.A. Davis. 7. Lehmann, JF, and Guy, AW: Ultrasound therapy. Proc Workshop on Interaction of Ultrasound and Biological 15. Young, H, and Freedman, R: Sears and Zemansky’s univer- Tissues, Washington, DC, HEW Pub. (FDA 73:8008), sity physics, Reading, MA, 2007, Addison-Wesley. Sept. 1972. Licht, S, editor: Electrodiagnosis and electromyography, ed 3, Suggested Readings New Haven, CT, 1971, Elizabeth Licht. Goodgold, J, and Eberstein, A: Electrodiagnosis of neuromuscular Licht, S: Therapeutic electricity and ultraviolet radiation, New diseases, Baltimore, MD, 1972, Williams & Wilkins. Haven, CT, 1959, Elizabeth Licht. Jehle, H: Charge fluctuation forces in biological systems, Ann NY Scott, P, and Cooksey, F: Clayton’s electrotherapy and actinother- Acad Sci 158:240–255, 1969. apy, London, 1962, Bailliere, Tindall and Cox. Koracs, R: Light therapy, Springfield, IL, 1950, Charles C Thomas.

2C H A P T E R Using Therapeutic Modalities to Affect the Healing Process William E. Prentice HOW SHOULD THE ATHLETIC TRAINER USE THERAPEUTIC Following completion of this chapter, MODALITIES IN the athletic training student will be REHABILITATION? able to: • Define inflammation and its associated signs T herapeutic modalities, when used appropri- ately, can be extremely useful tools in the reha- and symptoms. bilitation of the injured patient.17,24 Like any other tool, their effectiveness is limited by the • Clarify how therapeutic modalities should be knowledge, skill, and experience of the clinician used in rehabilitation of various conditions. using them. For the athletic trainer, decisions regarding how and when a modality may best be • Compare the physiological events associated incorporated should be based on a combination of with the different phases of the healing process. theoretical knowledge and practical experience. As a clinician, you should not use therapeutic modali- • Formulate a plan for how specific modalities ties at random, nor should you base their use on can be used effectively during each phase of what has always been done before. Instead, you healing and provide a rationale for their use. must always give consideration to what should work best in a specific injury situation. • Identify those factors that can interfere with the healing process. There are many different approaches and ideas regarding the use of modalities in injury rehabilita- tion. Therefore, no “cookbook” exists for modality use. In a given clinical situation, you as an athletic trainer should make your own decision about which modality will be most effective. In any program of rehabilitation, modalities should be used primarily as adjuncts to therapeutic exercise and certainly not at the exclusion of range- of-motion or strengthening exercises. Rehabilitation protocols and progressions must be based primarily on the physiological responses of the tissues to injury and on an understanding of how various tissues 17

18 PART ONE Foundations of Therapeutic Modalities heal (Figure 2–1).9 Thus, the athletic trainer must become a chronic injury? Generally injuries occur understand the healing process to be effective in either from trauma or from overuse. Acute injuries incorporating therapeutic modalities into the reha- are caused by trauma; chronic injuries can result bilitative process. from overuse as occurs with the repetitive dynamics of running, throwing, or jumping.33,35 Thus the terms In the physically active population, injuries most traumatic and overuse injuries are more appropriate. often involve the musculoskeletal system and in fewer instances the nervous system.1,8 Some healthcare In sports medicine, primary injuries are almost professionals have debated whether the terms acute always described as being either traumatic or overuse and chronic are appropriate in defining injury.13 At resulting from macrotraumatic or microtraumatic some point all injuries can be considered acute; in forces. Injuries classified as macrotraumatic occur as other words, there is always some beginning point for a result of trauma and produce immediate pain and every injury. At what point does an acute injury disability. Macrotraumatic injuries include fractures, TRAUMA Greater risk of reinjury PRIMARY INJURY Reduced risk of reinjury Hematoma Blood Damaged tissue SECONDARY RESPONSE Scab Edema Hypoxic damaged tissue Bleeding Return to activity Return to full activity INFLAMMATION Less than optimal Pain Optimal recovery recovery Guarding REPAIR PHASES Inflammation Fibroplastic Maturation Inadequate ATROPHY Adequate REHABILITATION Figure 2–1 A cycle of sport-related injury. (From Booher and Thibadeau, Athletic Injury Assessment, 1994)

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 19 The healing process is a continuum Signs of inflammation consisting of three phases • Redness • Inflammatory-response phase • Swelling • Fibroblastic-repair phase • Tenderness to touch • Maturation-remodeling phase • Increased temperature • Loss of function dislocations, subluxations, sprains, strains, and con- sound understanding of that process in terms of the tusions.30 Microtraumatic injuries are most often sequence of the phases of healing that take place.2 overuse injuries and result from repetitive overload- ing or incorrect mechanics associated with continu- The healing process consists of the inflammatory- ous training or competition. Microtraumatic injuries response phase, the fibroblastic-repair phase, and include tendinitis, tenosynovitis, bursitis, and so on. the maturation-remodeling phase. It must be A secondary injury is essentially the inflammatory or stressed that although the phases of healing are pre- hypoxia response that occurs with the primary sented as three separate entities, the healing process is injury.25 a continuum. Phases of the healing process overlap one another and have no definitive beginning or THE IMPORTANCE end points11 (Figure 2–2). The athletic trainer OF UNDERSTANDING should rely primarily on observation of the signs THE HEALING PROCESS and symptoms to determine how the healing pro- cess is progressing. The decisions made by the athletic trainer on how and when therapeutic modalities may best be used Inflammatory-Response Phase should be based on recognition of signs and symp- toms as well as some awareness of the time frames When you hear the term inflammation, you automat- associated with the different phases of the heal- ically think of something negative. The fact is that ing process.20,26 The athletic trainer must have a inflammation is a very important part of the healing process.23 Without the physiological changes that Maturation-remodeling phase Fibroblastic-repair phase (Strong contracted scar develops, increasing strength (diminishing pain and tenderness, gradual return to function) and full return to function) 2 days–6 weeks 3 weeks–2 years Inflammatory- response phase (Redness, swelling, tenderness, increased temperature, loss of function) 0–4 days Initial Time injury Figure 2–2 The three phases of the healing process fall along an overlapping time continuum.

20 PART ONE Foundations of Therapeutic Modalities take place during the inflammatory process, the the invading organism, some are released by the later stages of healing cannot occur. Once a tissue is damaged tissue, others are generated by several injured, the process of healing begins immediately.4 plasma enzyme systems, and still others are prod- The destruction of tissue produces direct injury to ucts of various white blood cells participating in the the cells of the various soft tissues. Cellular injury inflammatory response. Three chemical mediators, results in altered metabolism and the liberation of histamine, leukotrienes, and cytokines, are important materials that initiate the inflammatory response31 in limiting the amount of exudate, and thus swell- (Figure 2–3). ing, after injury.22 Histamine, released from the injured mast cells, causes vasodilation and increased Signs and Symptoms. It is characterized cell permeability, owing to a swelling of endothelial symptomatically by redness, swelling, tenderness, cells and then separation between the cells. Leuko- increased temperature, and loss of function.6,20 trienes and prostaglandins are responsible for margination, in which leukocytes (neutrophils Cellular Response. Inflammation is a process and macrophages) adhere along the cell walls. They during which leukocytes and other phagocytic also increase cell permeability locally, thus affecting cells and exudate are delivered to the injured tissue. the passage of the fluid and white blood cells through This cellular reaction is generally protective, tend- cell walls via diapedesis to form exudate. Therefore ing to localize or dispose of injury by-products (for vasodilation and active hyperemia are important in example, blood or damaged cells) through phagocy- tosis, thus setting the stage for repair. Locally, vas- leukocytes A white blood cell that is the primary cular effects, disturbances of fluid exchange, and effector cell against infection and tissue damage that migration of leukocytes from the blood to the tissues functions to clean up damaged cells. occur.14 phagocytic cells A cell that has the ability to Chemical Mediators. The events in the destroy and ingest cellular debris. inflammatory response are initiated by a series of interactions involving several chemical mediators.37 Some of these chemical mediators are derived from Wound Blood clot Epidermis of skin Dermis Macrophages of skin Fibroblast Neutrophils Leukocyte (A) Cut blood vessels bleed into the wound. (B) Blood clot forms, and leukocytes clean wound. Figure 2–3 Initial injury and inflammatory-response phase of the healing process.

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 21 Chemical mediators Thromboplastin released • Histamine • Leukotrienes Prothrombin • Cytokines Thrombin exudate (plasma) formation, in supplying leukocytes to the injured area. Cytokines, in particular chemo- Fibrinogen kines and interleukin, are the major regulators of leukocyte traffic and help to attract leukocytes to the Fibrin clot actual site of inflammation.16 Responding to the Figure 2–4 The clotting process involves a series of presence of chemokines, phagocytes enter the site of physiologic events that require as long as 48 hours to inflammation within a few hours. The amount of complete. swelling that occurs is directly related to the extent of vessel damage. of a protein molecule called thromboplastin, from the damaged cell. Thromboplastin causes pro- Vascular Reaction. The vascular reaction thrombin to be changed into thrombin, which in involves vascular spasm, the formation of a platelet turn causes the conversion of fibrinogen into a very plug, blood coagulation, and the growth of fibrous sticky fibrin clot that shuts off blood supply to the tissue.34 The immediate response to tissue damage injured area. Clot formation begins around 12 hours is a vasoconstriction of the vascular walls in the following injury and is completed by 48 hours18 vessels leading away from the site of injury that (Figure 2–4). lasts for approximately five to ten minutes. This vasoconstriction presses the opposing endothelial As a result of a combination of these factors, the wall linings together to produce a local anemia that injured area becomes walled off during the inflam- is rapidly replaced by hyperemia of the area due to matory stage of healing. The leukocytes phagocytize vasodilation. This increase in blood flow is transi- most of the foreign debris toward the end of the tory and gives way to slowing the flow in the dilated inflammatory phase, setting the stage for the fibro- vessels, thus enabling the leukocytes to slow down blastic phase. This initial inflammatory response and adhere to the vascular endothelium. Eventu- lasts for approximately 2 to 4 days following initial ally there is stagnation and stasis. The initial effu- injury (Figure 2–5). sion of blood and plasma lasts for twenty-four to thirty-six hours. Injury to cell The Function of Platelets. Platelets do not Chemical mediators liberated normally adhere to the vascular wall. However, (Histamine, Leukotrienes, Cytokines) injury to a vessel disrupts the endothelium and exposes the collagen fibers. Platelets adhere to the Vascular reaction collagen fibers to create a sticky matrix on the (Vasoconstriction Vasodilation Exudate creates stasis) vascular wall, to which additional platelets and leukocytes adhere and eventually form a plug. Platelets and leukocytes adhere to vascular wall These plugs obstruct local lymphatic fluid drainage and thus localize the injury response. Phagocytosis The Clotting Process. The initial event that Clot formation precipitates clot formation is the conversion of fibrinogen to fibrin.29 This transformation results Figure 2–5 The sequence of the inflammatory response. from a cascading effect, beginning with the release

22 PART ONE Foundations of Therapeutic Modalities Chronic Inflammation. A distinction must Fibroblastic-Repair Phase be made between the acute inflammatory response as previously described and chronic inflammation. During the fibroblastic phase of healing, proliferative Chronic inflammation occurs when the acute and regenerative activity leading to scar formation inflammatory response does not respond sufficiently and repair of the injured tissue follows the vascular to eliminate the injuring agent and restore tissue to and exudative phenomena of inflammation.15 The its nomal physiological state.13 Thus, only low con- period of scar formation referred to as fibroplasia centrations of the chemical mediators are present. begins within the first few hours following injury The neutrophils that are normally present during and may last for as long as 4 to 6 weeks. acute inflammation are replaced by macrophages, lymphocytes, fibroblasts, and plasma cells. As this Signs and Symptoms. During this period low-grade inflammation persists, damage occurs to many of the signs and symptoms associated with the connective tissue resulting in tissue necrosis and inflammatory response subside. The patient may fibrosis prolonging the healing and repair process. still indicate some tenderness to touch and will usu- Chronic inflammation involves the production of ally complain of pain when particular movements granulation tissue and fibrous connective tissue. stress the injured structure. As scar formation pro- These cells accumulate in a highly vascularized and gresses, complaints of tenderness or pain will gradu- innervated loose connective tissue matrix in the ally disappear.27 area of injury.21 The specific mechanisms that cause an insufficient acute inflammatory response are Revascularization. During this phase, unknown, but they appear to be related to situations growth of endothelial capillary buds into the wound that involve overuse or overload with cumulative is stimulated by a lack of oxygen. Thus, the wound microtrauma to a particular structure.10,21 There is is now capable of healing aerobically. Along with no specific time frame in which the acute inflamma- increased oxygen delivery comes an increase in tion transitions to chronic inflammation. It does blood flow, which delivers nutrients essential for appear that chronic inflammation is resistant to tissue regeneration in the area7 (Figure 2–6). both physical and pharmacologic treatments.19 Formation of Scar. The formation of a deli- In chronic inflammation, neutrophils cate connective tissue called granulation tissue are replaced with occurs with the breakdown of the fibrin clot. Granu- lation tissue consists of fibroblasts, collagen, and • Macrophages capillaries. It appears as a reddish granular mass of • Lymphocytes connective tissue that fills in the gaps during the • Fibroblasts healing process. • Plasma cells As the capillaries continue to grow into the ■ Analogy 2–1 area, fibroblasts accumulate at the wound site, arranging themselves parallel to the capillaries. The physiologic events that occur during the Fibroblastic cells begin to synthesize an extracellular inflammatory-response phase are similar to creating matrix, which contains protein fibers of collagen and rebuilding a fort. The injured area is essentially and elastin, a ground substance that consists of shut off from the outside environment, and soldiers nonfibrous proteins called proteoglycans, glycos- (phagocytic cells) come inside the fort to clean up the aminoglycans, and fluid. On about day 6 or 7, fibro- debris before the reinforcement troops (fibroblastic cells) blasts also begin producing collagen fibers that are show up to rebuild the structures inside. deposited in a random fashion throughout the fibroplasia The period of scar formation that occurs during the fibroblastic-repair phase.

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 23 Blood clot ■ Analogy 2–2 Granulation The physiologic events that occur during the fibroblastic- tissue repair phase are similar to taking spaghetti out of a pot Macrophages of boiling water and laying it on a table at random. Regrowth of Initially the spaghetti is weak and tender. In a short blood vessel time, the spaghetti begins to dry out and becomes more Fibroblast solid, a little dryer, and harder to disturb (as in the tran- sition between the fibroblastic repair and maturation- Figure 2–6 Blood vessels regrow, and granulation remodeling phases). tissue forms in the fibroblastic-repair phase of the healing process. Fibrosis can occur in synovial structures, as is the case with adhesive capsulitis in the shoulder; in forming scar. As the collagen continues to prolifer- extra-articular tissues, including tendons and liga- ate, the tensile strength of the wound rapidly ments; in bursa; or in muscle. increases in proportion to the rate of collagen syn- thesis. As the tensile strength increases, the number A mature scar will be devoid of physiologic of fibroblasts diminishes to signal the beginning of function, it will have less tensile strength than the the maturation phase.5 original tissue, and it is not as well vascularized. This normal sequence of events in the repair Maturation-Remodeling Phase phase leads to the formation of minimal scar tissue. Occasionally, a persistent inflammatory response The maturation-remodeling phase of healing is a and continued release of inflammatory products can long-term process. This phase features a realign- promote extended fibroplasia and excessive fibro- ment or remodeling of the collagen fibers that genesis that can lead to irreversible tissue damage.21 make up the scar tissue according to the tensile forces to which that scar is subjected (Figure 2–7). Granulation tissue consists of • Capillaries Scab • Collagen • Fibroblasts Regenerated epithelium (epidermis) Scar tissue (fibrosis) Fibroblast The extracellular matrix contains Figure 2–7 Epithelium regenerates, and connective tissue fibrosis occurs in the maturation-remodeling phase • Collagen of the healing process. • Elastin • Ground substance

24 PART ONE Foundations of Therapeutic Modalities Ongoing breakdown and synthesis of collagen occur microtears Minor damage to soft tissue most often with a steady increase in the tensile strength of the associated with overuse. scar matrix. With increased stress and strain, the collagen fibers will realign in a position of maximum macrotears Significant damage to the soft tissues efficiency parallel to the lines of tension.38 The tis- caused by acute trauma that results in clinical symp- sue gradually assumes normal appearance and toms and functional alterations. function, although a scar is rarely as strong as the normal injured tissue. Usually by the end of approxi- produces reflexive neurological changes, and mately 3 weeks, a firm, strong, contracted, nonvas- impedes nutrition in the injured part. Edema is best cular scar exists. The maturation phase of healing controlled and managed during the initial first aid may require several years to be totally complete. management period.37 FACTORS THAT IMPEDE Hemorrhage. Bleeding occurs with even the HEALING smallest amount of damage to the capillaries. Bleed- ing produces the same negative effects on healing as See Table 2–1 for a list of factors that impede does the accumulation of edema, and its presence healing. produces additional tissue damage and thus exacer- bation of the injury.29 Extent of Injury. The nature or amount of the inflammatory response is determined by the Poor Vascular Supply. Injuries to tissues extent of the tissue injury. Microtears of soft tissue with a poor vascular supply heal poorly and at a involve only minor damage and are most often slow rate. This is likely related to a failure in the associated with overuse. Macrotears involve sig- delivery of phagocytic cells initially and also of fibro- nificantly greater destruction of soft tissue and blasts necessary for formation of scar. result in clinical symptoms and functional altera- tions. Macrotears are generally caused by acute Separation of Tissue. Mechanical separa- trauma. tion of tissue can significantly impact the course of healing. A wound that has smooth edges that are in Edema. The increased pressure caused by good apposition will tend to heal by primary inten- swelling retards the healing process, causes separa- tion with minimal scarring. Conversely, a wound tion of tissues, inhibits neuromuscular control, that has jagged separated edges must heal by second intention, with granulation tissue filling the defect TABLE 2–1 Factors That Impede Healing and causing excessive scarring.28 Extent of injury Muscle Spasm. Muscle spasm causes trac- Edema tion on the torn tissue, separates the two ends, and Hemorrhage prevents approximation. Both local and generalized Poor vascular supply ischemia may result from spasm. Separation of tissue Muscle spasm ■ Analogy 2–3 Atrophy Corticosteroids The physiologic events that occur during the maturation- Keloids and hypertrophic scars remodeling phase are similar to an artist sculpting a Infection statue out of a mass of clay. As the artist’s hands pro- Humidity, climate, and oxygen tension duce stresses and strains on the clay, it is reshaped and Health, age, and nutrition realigned until the artist is satisfied with the finished product (as would occur when the athletic trainer incorporates specific therapeutic exercises designed to realign collagen fibers along lines of tensile force).

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 25 Atrophy. Wasting away of muscle tissue vitamins A and E, zinc, and amino acids play critical begins immediately with injury. Strengthening and roles in the healing process. early mobilization of the injured structure retards atrophy. HOW SHOULD THERAPEUTIC MODALITIES BE USED Corticosteroids. Use of corticosteroids such THROUGHOUT THE as cortisone in the treatment of inflammation is con- REHABILITATION PROCESS? troversial. Steroid use in the early stages of healing has been demonstrated to inhibit fibroplasia, capil- Using Modalities in the Immediate lary proliferation, collagen synthesis, and increases First Aid Management of Injury in tensile strength of the healing scar. Their use in the later stages of healing and with chronic inflam- Table 2–2 summarizes the various modalities that mation is debatable. may be used in the different phases of the healing process. Modality use in the initial treatment of injury Keloids and Hypertrophic Scars. Keloids should be directed toward limiting the amount of occur when the rate of collagen production exceeds swelling and reducing pain that occurs acutely. The the rate of collagen breakdown during the matura- acute phase is marked by swelling, pain to touch tion phase of healing. This process leads to hyper- or with pressure, and pain on both active and pas- trophy of scar tissue, particularly around the sive motion. In general, the less initial swelling, the periphery of the wound, that is out of proportion to less the time required for rehabilitation. Tradition- normal scarring. The result is a raised, firm, thick- ally, the modality of choice has been and still is RICE ened, red scar. (rest, ice, compression, elevation). Infection. The presence of bacteria in the Cryotherapy is known to produce vasocon- wound can delay healing, can cause excessive gran- striction, at least superficially and perhaps indi- ulation tissue, and can frequently cause large rectly in the deeper tissues, and thus limits the deformed scars. bleeding that always occurs with injury. Ice bags, cryocuffs, cold packs, and ice massage may all be Humidity, Climate, and Oxygen Tension. used effectively. Cold baths should be avoided Humidity significantly influences the process of epi- because the extremities must be placed in a gravity- thelization. Occlusive dressings stimulate the epi- dependent position. Cold whirlpools also place the thelium to migrate twice as fast without crust or extremities in the gravity-dependent position and scab formation. The formation of a scab occurs with produce a massaging action that is likely to retard dehydration of the wound and traps wound drain- clotting. The importance of applying ice immedi- age, which promotes infection. Keeping the wound ately following injury for limiting acute swelling moist provides an advantage for the necrotic debris through vasoconstriction has probably been over- to go to the surface and be shed. emphasized. The initial use of ice is more important for decreasing the secondary hypoxic response asso- Oxygen tension relates to the neovasculariza- ciated with tissue injury (see Chapter 4). Analgesia, tion of the wound, which translates into optimal which occurs through stimulation of sensory cuta- saturation and maximal tensile strength develop- neous nerves via the gating mechanism, blocks or ment. Circulation to the wound can be affected by reduces pain. ischemia, venous stasis, hematomas, and vessel trauma. Immediate compression has been demon- strated to be an effective technique for limiting Health, Age, and Nutrition. The elastic qualities of the skin decrease with aging. Degenera- tive diseases, such as diabetes and arteriosclerosis, also become a concern of the older patient and may affect wound healing. Nutrition is important for wound healing. In particular, vitamin C, vitamin K,

26 PART ONE Foundations of Therapeutic Modalities TABLE 2–2 Athletic Training Decision-Making on the Use of Various Therapeutic Modalities in Treatment of Acute Injury PHASE CLINICAL PICTURE POSSIBLE RATIONALE FOR USE APPROXIMATE (SIGNS AND TIME FRAME SYMPTOMS) MODALITIES USED Injury– day 3 Initial acute Swelling, pain to touch, CRYO ↓ Swelling, ↓ pain Day 1– day 6 pain on motion ESC ↓ Pain IC ↓ Swelling Day 4 – day 10 LPL ↓ Pain ULTRA Nonthermal effects to ↑ Day 7–recovery Rest healing Inflammatory Swelling subsides, warm CRYO ↓ Swelling, ↓ pain response ↓ Pain to touch, discoloration, ESC ↓ Swelling ↓ Pain pain to touch, pain on IC Nonthermal effects to ↑ motion LPL healing ULTRA Mildly ↑ circulation ↓ Pain—muscle pumping Fibroblastic-repair* Pain to touch, pain on Range of motion ↓ Pain motion, swollen THERMO Facilitate lymphatic flow ESC Nonthermal effects to ↑ LPL IC healing ULTRA Deep heating to ↑ Range of motion circulation Strengthening ↑ Range of motion, ↑ strength Maturation- Swollen, no more pain to ULTRA remodeling* ↓ Pain touch, decreasing pain ↓ Pain Deep heating to ↑ on motion ESC circulation LPL Deep heating to ↑ SWD MWD circulation Range of motion Strenghtening Functional activities CRYO, Cryotherapy; ESC, electrical stimulating currents; IC, intermittent compression; LPL, low-power laser; MWD, microwave diathermy; SWD, shortwave diathermy; THERMO, thermotherapy; ULTRA, ultrasound; ↓, decrease; ↑, increase. *Anti-inflammatory medication prescribed by the physician is recommended. swelling. An intermittent compression device may reduces the amount of space available for swelling be used to provide even pressure around an injured to accumulate. Units that combine both compres- extremity. The pressurized sleeve mechanically sion and cold have been shown to be more effective

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 27 in reducing swelling than using compression alone. massages provide analgesic effects. The use of cold Regardless of the specific techniques selected (see also reduces the likelihood of swelling, which may Chapter 13), cold and compression should always continue during this stage. Swelling does subside be combined with elevation to avoid any additional completely by the end of this phase. pooling of blood in the injured area due to the effects of gravity. It must be emphasized that heating an injury too soon is a bigger mistake than using ice on an Electrical stimulating currents may also be used injury for too long. Many athletic trainers elect to in the initial phase for pain reduction. Parameters stay with cryotherapy for weeks following injury; in should be adjusted to maximally stimulate sensory fact, some never switch to the superficial heating cutaneous nerve fibers, again to take advantage of techniques. This procedure is simply a matter of per- the gate control mechanism of pain modulation. sonal preference that should be dictated by experi- Intensities that produce muscle contractions should ence. Once swelling has stopped, the athletic trainer be avoided because they may increase clotting time may elect to begin contrast baths with a longer (see Chapter 5). cold-to-hot ratio. Low-intensity ultrasound has been demon- An intermittent compression device may be strated to be effective in facilitating the healing pro- used to decrease swelling by facilitating resorption cess when used immediately following injury and of the by-products of inflammatory process by the certainly within the first 48 hours. Low intensities lymphatic system. Electrical stimulating currents produce nonthermal physiologic effects that alter and low-power laser can be used to help reduce the permeability of cell membranes to sodium and pain. calcium ions important in healing (see Chapter 8). After the initial stage, the patient should begin The low-power laser has also been shown to be to work on active and passive range of motion. effective in pain modulation through the stimula- Decisions regarding how rapidly to progress exer- tion of trigger points and may be used acutely (see cise should be determined by the response of the Chapter 10). injury to that exercise. If exercise produces addi- tional swelling and markedly exacerbates pain, The injured part should be rested and protected then the level or intensity of the exercise is too for at least the first 48 to 72 hours to allow the great and should be reduced. Athletic trainers inflammatory phase of the healing process to do should be aggressive in their approach to rehabili- what it is supposed to. tation, but the healing process will always limit the approach. Modality Use in the Inflammatory-Response Phase Modality Use in the Fibroblastic-Repair Phase The inflammatory-response phase begins immedi- ately with injury and may last as long as day 6 fol- Once the inflammatory response has subsided, the lowing injury. With appropriate care, swelling be- fibroblastic-repair phase begins. This stage may gins to subside and eventually stops altogether. The begin as early as 4 days after the injury and may last injured area may feel warm to the touch, and some for several weeks. At this point, swelling has stopped discoloration is usually apparent. The injury is still completely. The injury is still tender to the touch but painful to the touch, and pain is elicited on move- is not as painful as during the last stage. Pain is also ment of the injured part. less on active and passive motion. As in the initial injury management stage, Treatments may change during this stage modalities should be used to control pain and reduce from cold to heat, once again using increased swell- swelling. Cryotherapy should still be used during ing as a precautionary indicator. Thermotherapy the inflammatory stage. Ice bags, cold packs, or ice

28 PART ONE Foundations of Therapeutic Modalities Clinical Decision-Making Exercise 2–1 At this point some type of heating modality is beneficial to the healing process. The deep-heating A female soccer player sprains her ankle, and the modalities, ultrasound, or short-wave and micro- team physician diagnoses it as a grade 1 sprain. wave diathermy should be used to increase circula- The coach wants to know how long the athlete tion to the deeper tissues. Ultrasound is particu- will be out. On what information should the larly useful during this period since collagen athletic trainer base his or her response? absorbs a high percentage of the available acoustic energy. Increased blood flow delivers the essential techniques including hydrocollator packs, paraffin, nutrients to the injured area to promote healing, or eventually warm whirlpool may be safely and increased lymphatic flow assists in breakdown employed. The purpose of thermotherapy is to and removal of waste products. The superficial increase circulation to the injured area to promote heating modalities are certainly less effective at healing. These modalities can also produce some this point. degree of analgesia. Electrical stimulating currents can be used for Intermittent compression can once again be a number of purposes. As before, they may be used used to facilitate removal of injury by-products from in pain modulation. They may also be used to stim- the area. Electrical stimulating currents can be used ulate muscle contractions for the purpose of to assist this process by eliciting a muscle contrac- increasing both range of motion and muscular tion and thus inducing a muscle pumping action. strength.12 This aids in facilitating lymphatic flow. Electrical currents can once again be used for modulation of Low-power laser can also assist in modulating pain, as can stimulation of trigger points with the pain. If pain is reduced, therapeutic exercises may be low-powered laser. progressed more quickly. The athletic trainer must continue to stress the The Role of Progressive Controlled Mobil- importance of range-of-motion and strengthening ity in the Maturation Phase. Wolff’s Law exercises and progress them appropriately during states that bone will respond to the physical this phase. demands placed upon it, causing it to remodel or realign along lines of tensile force.36 Although not Modality Use in the specified in Wolff’s Law, the same response occurs Maturation-Remodeling Phase in soft tissue. Therefore, it is critical that injured structures be exposed to progressively increasing The maturation-remodeling phase is the longest loads, particularly during the remodeling phase. of the four phases and may last for several years, Controlled mobilization has been shown to be supe- depending on the severity of the injury. The ul- rior to immobilization for scar formation, revascu- timate goal during this maturation stage of the larization, muscle regeneration, and reorientation healing process is return to activity. The injury of muscle fibers and tensile properties in animal is no longer painful to the touch, although some models.2 However, immobilization of the injured progressively decreasing pain may still be felt on tissue during the inflammatory-response phase motion. The collagen fibers must be realigned ac- will likely facilitate the process of healing by cording to tensile stresses and strains placed upon controlling inflammation, thus reducing athletic them. Virtually all modalities may be safely used training symptoms. As healing progresses to the during this stage; thus, decisions should be based repair phase, controlled activity directed toward on what seems to work most effectively in a given return-to-normal flexibility and strength should be situation. combined with protective support or bracing. Gen- erally, clinical signs and symptoms disappear at the end of this phase.

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 29 Clinical Decision-Making Exercise 2–2 Clinical Decision-Making Exercise 2–4 A patient is 8 days post strain of the quadriceps The athletic trainer decides to allow a patient with muscle of the thigh. The athletic trainer feels that it a grade 1 ankle sprain to be full weight bearing is time to change from cold therapy to some form of immediately following injury. Is this the best heat. What criteria should be used to determine if decision based on your knowledge of the healing this patient is ready to change to heat? process? Clinical Decision-Making Exercise 2–3 great for the level of tissue repair or remodeling. The athletic trainer must be aware of the timelines In the rehabilitative process for a sprain of the required for the process of healing and realize that medial collateral ligament in the knee, at what being overly aggressive can interfere with that point should the athletic trainer decide to add process. therapeutic exercises to modality use? OTHER CONSIDERATIONS As the remodeling phase begins, aggressive IN TREATING INJURY active range-of-motion and strengthening exer- cises should be incorporated to facilitate tissue During the rehabilitation period following injury, remodeling and realignment.39 To a great extent, athletes must alter their daily routines to allow the pain will dictate rate of progression. With initial injury to heal sufficiently. Consideration must be injury, pain is intense and tends to decrease and given to maintaining levels of strength, flexibility, eventually subside altogether as healing pro- neuromuscular control, balance, and cardiorespira- gresses. Any exacerbation of either pain, swelling, tory endurance. Modality use should be combined or other symptoms during or following a particu- with the use of anti-inflammatory medications pre- lar exercise or activity indicates that the load is too scribed by the physician, particularly during the initial acute and inflammatory-response phases of rehabilitation.3 Summary 1. Clinical decisions on how and when therapeutic 4. Modality use in the initial treatment phase modalities may best be used should be based on should be directed toward limiting the amount recognition of signs and symptoms, as well as of swelling and reducing pain. some awareness of the time frames associated with the various phases of the healing process. 5. It is critical to use logic and common sense based on sound theoretical knowledge when 2. Once an acute injury has occurred, the healing selecting the appropriate modalities to use dur- process consists of the inflammatory-response ing the different phases of healing. phase, the fibroblastic-repair phase, and the maturation-remodeling phase. 6. During the rehabilitation period after injury, patients must alter their training and con- 3. A number of pathologic factors can impede the ditioning habits to allow the injury to heal healing process. sufficiently.

30 PART ONE Foundations of Therapeutic Modalities Review Questions 1. How should the athletic trainer incorporate 6. What are some of the factors that can have a therapeutic modalities into a rehabilitation negative impact on the healing process? program for various sports-related injuries? 7. Why is the immediate care provided following 2. What are the physiological events associated acute injury so important to the healing pro- with the inflammatory-response phase of the cess and the course of rehabilitation? healing process? 8. What specific modalities may be incorporated 3. How can you differentiate between acute and into treatment during the inflammatory- chronic inflammation? response phase? 4. How is collagen laid down in the area of injury 9. What specific modalities may be incorporated during the fibroblastic-repair phase of healing? into treatment during the fibroblastic-repair phase? 5. Explain Wolff ’s Law and the importance of controlled mobility during the maturation- 10. What are the specific indications and contra- remodeling phase of healing. indications for using the various modalities? Self-Test Questions True or False 7. During the inflammatory-response phase of 1. Loss of function is a sign of the inflammatory the healing process, modalities are used to process. a. control pain 2. Leukocytes are present in both the acute and b. reduce swelling chronic inflammatory responses. c. both a and b 3. An injured individual’s health, age, and nutri- d. neither a nor b tion are factors that influence healing. 8. states that bone and soft tissue Multiple Choice remodel and realign according to the physical 4. The three phases of the healing process, in demands placed upon them. order, are as follows: a. Wolff’s Law a. Fibroblastic-repair, inflammatory-response, b. Ohm’s Law maturation-remodeling c. Meissner’s Law b. Inflammatory-response, fibroblastic-repair, d. McGill’s Law maturation-remodeling c. Inflammatory-response, maturation- 9. Approximately how long does the maturation- remodeling, fibroblastic-repair remodeling phase of the healing process last? 5. Which of the following type of cell has phago- a. less than 1 week cytic characteristics? b. 1 week a. red blood cells c. 1 to 2 weeks b. platelets d. 3 weeks to 2 years c. leukocytes d. endothelials 10. Which of the following is NOT a chemical me- 6. The extracellular matrix, formed by fibroblastic diator involved in the inflammatory-response cells, consists of phase? a. collagen a. testosterone b. elastin b. histamine c. ground substance c. necrosin d. all of the above d. leukotaxin

CHAPTER 2 Using Therapeutic Modalities to Effect the Healing Process 31 Solutions to Clinical Decision-Making Exercises 2–1 The athletic trainer’s response should be so on) have disappeared, and thus it should based on knowledge of the healing process be safe to go with heat. If changing to heat and an understanding of the time frames nec- causes the patient to have greater difficulty essary in that process. completing strengthening and flexibility ex- ercises, then the change has likely been made 2–2 The athletic trainer should use cryotherapy too quickly. and some type of compression device, along 2–4 Knowing how important it is for the inflam- with elevation, to control swelling initially. matory-response phase to accomplish what it Additionally, electrical stimulating currents needs to physiologically without interference, may be used to help provide analgesia, and it is likely best to recommend minimal weight ultrasound can be used to facilitate healing. bearing for the first 24 to 48 hours. 2–5 Therapeutic exercises should begin on day 1 2–3 At this point, the patient is in transition be- following injury. The point is that modalities tween the fibroblastic-repair phase and the should be used to facilitate the patient’s effort maturation-remodeling phase. Although to actively exercise the injured part and not in there is still some pain on active motion, all of place of the active exercise. the clinical signs of inflammation (tenderness to touch, increased warmth, redness, and 13. Grichnick, K, and Ferrante, F: The difference between acute and chronic pain, Mt. Sinai Journal of Medicine, References 58:217, 1991. 1. Allen, T: Exercises-induced muscle damage: mechanisms, 14. Hart, J: Inflammation: its role in the healing of acute prevention, and treatment. Physiotherapy Can 56(2):67– wounds, J Wound Care 11(6):205–209, 2002. 79, 2004. 15. Hettinga, D: Inflammatory response of synovial joint struc- 2. Arnoczky, SP: Physiologic principles of ligament injuries tures. In Gould J, and Davies, G, editors: Orthopaedic and and healing. In Scott, WN, editor: Ligament and extensor sports physical therapy, St. Louis, 1990, Mosby. mechanism injuries of the knee, St. Louis, 1991 Mosby. 16. Hildebrand, K, Behm, C, and Kydd, A: The basics of 3. Biederman, R: Pharmacology in rehabilitation: nonste- soft tissue healing and general factors that influence roidal anti-inflammatory agents. J Orthop Sports Phys Ther such healing, Sports Medicine and Arthroscopy Review, 35(6):356–367, 2005. 13(3):136–144, 2005. 4. Bryant, MW: Wound healing, CIBA Clin Symp 29(3): 17. Houghton, PE: Effects of therapeutic modalities on wound 2–36, 1997. healing: a conservative approach to the management of chronic wounds, Phys Ther Rev 4(3):167–182, 1999. 5. Cailliet, R: Soft tissue pain and disability, ed 3, Philadelphia, 1996, FA Davis. 18. Houglum, P: Soft tissue healing and its impact on rehabili- tation, J Sport Rehab 1(1):19–39, 1992. 6. Carrico, T, Mehrhof, A, and Cohen, I: Biology and wound healing, Surg Clin North Am 64(4):721–734, 1984. 19. Hubbel, S, and Buschbacher, R: Tissue injury and healing: using medications, modalities, and exercise to maximize 7. Cheng, N: The effects of electrocurrents on A.T.P. genera- recovery. In Bushbacher, R, and Branddom, R, editors: tion, protein synthesis and membrane transport, J. Orthop. Sports medicine and rehabilitation: a sport specific approach, Rel. Res. 171:264–272, 1982. Philadelphia, 1994, Hanley & Belfus. 8. Clarkson, PM, and Tremblay I: Exercise-induced muscle 20. Leadbetter, W, Buckwalter, J, and Gordon, S: Sports-induced damage, repair and adaptation in humans, J Appl Physiol inflammation, Park Ridge, IL, 1990, American Academy of 65:1–6, 1988. Orthopaedic Surgeons. 9. Damjanov, I: Anderson’s pathology, ed 10, St. Louis, 1996, 21. Leadbetter, W: Introduction to sports-induced soft-tissue Mosby. inflammation. In Leadbetter, W, Buckwalter, J, and Gordon, S., editors: Sports-induced inflammation, Park Ridge, IL, 10. Fantone, J: Basic concepts in inflammation. In Leadbetter, 1990, American Academy of Orthopaedic Surgeons. W, Buckwalter, J, and Gordon, S, editors: Sports-induced inflammation, Park Ridge, IL, 1990, American Academy 22. Ley, K. Physiology of inflammation, Bethesda, MD, 2001, of Orthopaedic Surgeons. American Physiological Society. 11. Fernandez, A, and Finlew, J: Wound healing: helping a natural process, Postgrad Med 74(4):311–318, 1983. 12. Fleischli, JG, Laughlin, TJ: Electrical stimulation in wound healing, J. Foot Ankle Surg 36:457, 1997.

32 PART ONE Foundations of Therapeutic Modalities 23. Marchesi, V.: Inflammation and healing. In Danjanov, I, Sports-induced inflammation, Park Ridge, IL, 1990, Ameri- editor: Anderson’s pathology, ed 10, St. Louis, Mosby, 1996. can Academy of Orthopaedic Surgeons. 33. Weintraub, W: Tendon and ligament healing: a new 24. Montbriand, D: Rehab products: equipment focus. Making approach to sports and overuse injury, St. Paul, 2003, progress: modalities can jumpstart the healing process, Paradigm Publications. Advanced Magazine for Directors of Rehabilitation 11(7): 34. Wahl, S, and Renstrom, P: Fibrosis in soft tissue injuries. In 69–70, 72, 80, 2002. Leadbetter, W, Buckwalter, J, and Gordon, S: Sports-induced inflammation, Park Ridge, IL, 1990, American Academy of 25. Peterson, L, and Renstrom, P. Injuries in musculoskeletal Orthopaedic Surgeons. tissues. In Peterson, L, editor: Sports injuries: their prevention 35. Wilder, R. Overuse injuries: tendinopathies, stress frac- and treatment, ed 3, Champaign, IL, Human Kinetics, 2001. tures, compartment syndrome, and shin splints, Clin Sports Med 23(1):55–81, 2004. 26. Prentice, W: Arnheim’s principles of athletic training, ed 13, 36. Wolff, J: Gesetz der transformation der knochen, Berlin, 1892, San Francisco, McGraw-Hill, 2008. Aug. Hirschwald. 37. Woo, SL-Y, and Buckwalter, J: editors: Injury and repair of 27. Riley, W: Wound healing, Am Fam. Phys 24:5, 1981. musculoskeletal soft tissues, Park Ridge, IL, 1988, American 28. Robbins, S, Cotran, R, and Kumar, V: Pathologic basis of Academy of Orthopaedic Surgeons. 38. Young, T: The healing process, Pract Nurs 22(10):38, 40, disease, ed 3, Philadelphia, 1984, WB Saunders. 43, 2001. 29. Rywlin, A: Hemopoietic system. In Damjanov, I., editor: 39. Zachezewski, J: Flexibility for sports. In Sanders, B., editor: Sports physical therapy, Norwalk, CT, 1990, Appleton & Anderson’s Pathology, ed 10, St. Louis, Mosby, 1996. Lange. 30. Soto-Quijano, D: Work-related musculoskeletal disorders of the upper extremity, Crit Rev Phys Rehab Med 17(1): 65–82, 2005. 31. Udermann, BE: Inflammation: the body’s response to injury, Int. Sports J 3(2)19–24, 1999. 32. Wahl, S, and Renstrom, P: Fibrosis in soft-tissue injuries. In Leadbetter, W, Buckwalter, J, and Gordon, S, editors:

3C H A P T E R Managing Pain with Therapeutic Modalities Craig R. Denegar and William E. Prentice Following completion of this chapter, UNDERSTANDING PAIN the athletic training student will be able to: • Compare the various types of pain and appraise T he International Association for the Study of Pain defines pain as “an unpleasant sensory and their positive and negative effects. emotional experience associated with actual or potential tissue damage, or described in terms of • Choose a technique for assessing pain. such damage.”29 Pain is a subjective sensation with more than one dimension and an abundance of • Analyze the characteristics of sensory receptors. descriptors of its qualities and characteristics. In spite of its universality, pain is composed of a variety • Examine how the nervous system relays of human discomforts, rather than being a single information about painful stimuli. entity.28 The perception of pain can be subjectively modified by past experiences and expectations. • Distinguish between the different Much of what we do to treat patients’ pain is to neurophysiologic mechanisms for pain control change their perceptions of pain.5 for the therapeutic modalities used by athletic trainers. Pain does have a purpose. It warns us that something is wrong and can provoke a withdrawal • Predict how pain perception can be modified response to avoid further injury. It also results in by cognitive factors. muscle spasm and guards or protects the injured part. Pain, however, can persist after it is no longer useful. It can become a means of enhancing dis- ability and inhibiting efforts to rehabilitate the patient.14 Prolonged spasm, which leads to circu- latory deficiency, muscle atrophy, disuse habits, and conscious or unconscious guarding, may lead to a severe loss of function.23 Chronic pain may become a disease state in itself. Often lacking an identifiable cause, chronic pain can totally disable a patient. Research in recent years has led to a better understanding of pain and pain relief. This research also has raised new questions, while leaving many unanswered. We now have better explanations for the analgesic properties of the physical agents we 33