With more than 200,000 athletes each year suffering noncontact injury to the anterior cruciate ligament (ACL) of the knee, there is finally an up-to-date reference for professionals whose work involves developing and implementing programs to prevent such injuries. Understanding and Preventing Noncontact ACL Injuries provides an authoritative description of the biomechanical, clinical, and injury factors pertinent to the athletes—primarily girls and young women—who experience this problem. To help readers understand how to incorporate targeted interventions, the book uses a preventive rather than strictly clinical approach to ACL injuries. It provides a thorough description of the current problem on an international scale, the rationale for developing prevention programs, the discrete risk factors for noncontact ACL injuries, and an analysis of current research data on the effects of interventions designed to prevent these injuries. Understanding and Preventing Noncontact ACL Injuries will help readers -clearly understand the incidence, cost, and need to quantify risk factors related to the onset of noncontact ACL injuries; -compare various prevention programs and learn why prevention programs should be implemented—especially among young women—to reduce the potential for injury; and -understand the interplay between biomechanical and neuromuscular risk factors and become aware of the role hormones, bracing, and biofeedback play. Understanding and Preventing Noncontact ACL Injuries is based on proceedings from a conference conducted by the American Orthopaedic Society for Sports Medicine and draws on the work of renowned experts in the field. The book logically progresses through four parts to help physicians, professionals, coaches, and other readers better understand the problem and how they may play a part in its prevention. Part I addresses the problem of ACL injuries, including the incidence of injury, risk factors, and costs associated with injuries. Part II examines injury prevention programs, their similarities and differences, and their relative effectiveness. Part III presents the latest information on biomechanical and neuromuscular mechanisms of ACL injuries. Part IV explores hormonal and anatomic risk factors and preventive bracing for ACL injuries. To illustrate the preventive approaches that may be used, the book contains photographs of individuals actually performing the progressions involved in the programs. Other helpful resources include take-home messages and clinical notes that relate scientific findings to successful preventive efforts. By providing these tools, the authors hope to provide an easy-to-understand reference that appeals to a broad range of individuals, including athletic directors, coaches, parents, and athletes who would like to learn more about how to implement prevention programs in their schools or other organizations. Understanding and Preventing Noncontact ACL Injuries is a current and unique resource that will be useful for all people affected by this global issue. By combining scientific factors with injury mechanisms, the book will provide readers with valuable knowledge of ACL injuries and help readers implement programs to prevent them.

Table of Contents:
An Introduction to Understanding and Preventing ACL Injury Timothy Edwin Hewett, PhD, FACSM Summary Part I. The Problem of ACL Injuries Part Editor: Letha Y. Griffin, MD, PhD Chapter 1. Incidence of ACL Injury Stephen W. Marshall, PhD; Darin Padua, PhD, ATC; and Melanie McGrath, MS, ATC Human Movement and ACL Injury What Is Incidence? What Is the Average Incidence of ACL Injury in the General Population? National Ambulatory Care Surveys Summary How Does ACL Injury Incidence Vary by Age and Gender? How Does the Incidence of ACL Injury Vary By Sport and Gender? Literature Review Methods Abstraction of Incidence Data General Results Synthesis and Commentary Conclusions Recommendations for Future Research Chapter 2. Does ACL Reconstruction Prevent Articular Degeneration? The ACL Risk Equation Paul H. Marks, MD; Kurt P. Droll, MD; and Michelle Cameron-Donaldson, MD Meniscal Pathology Osteochondral Pathology Impaired Proprioception Biochemical Mediators Summary and Future Work Chapter 3. The Costs Associated With ACL Injury Timothy Edwin Hewett, PhD, FACSM; and Bohdanna T. Zazulak, DPT, MS, OCS Who Pays for ACL Injury Prevention in the High-Risk Female Athlete? Informing the High-Risk Female Athlete Summary Part II. ACL Injury Prevention Programs Part Editor: Timothy E. Hewett, PhD, FACSM Chapter 4. Components of Prevention Programs Holly J. Silvers, MPT Chapter 5. Theories on How Interventions May Influence ACL Injury Rates: The Biomechanical Effects of Plyometric, Balance, Strength, and Feedback Training Timothy Edwin Hewett, PhD, FACSM; Gregory D. Myer, MS, CSCS; and Kevin R. Ford, MS Single-Component Training Multicomponent Training Effects of a Comprehensive Program Combined With Either Plyometric or Balance Training Components Conclusions and Future Directions Chapter 6. Preventive Training Programs: Changing Strength Ratios Versus Positions of Muscular Efficiency Sandra J. Shultz, PhD, ATC, CSCS Thigh Strength Hip Strength Core Strength Summary Chapter 7. Effect of Prevention Programs on Performance Christopher M. Powers, PhD, PT; Christine D. Pollard, PhD, PT; and Susan M. Sigward, PhD, PT, ATC Performance Measure: Vertical Jump Height Performance Measures: Agility, Strength and Lunge Distance Performance Measures: Vertical Jump Height, Single-Leg Hop, Speed, and Strength Performance Measure: Single-Limb Stability Performance Measures: Balance, Strength, Single-Leg Hop, Triple Jump, and Stair Hop Summary Chapter 8. Congruence Between Existing Prevention Programs and Research on Risk Factors and Mechanisms of Noncontact ACL Injury William E. Garrett, Jr., MD, PhD; and Bing Yu, PhD ACL Loading Mechanisms and Risk Factors of Noncontact ACL Injury Current Training Programs Future Training Program Development Chapter 9. Discussion, Summary, and Future Research Goals Lars Engebretsen, MD, PhD Part III. Biomechanical and Neuromuscular Mechanisms of ACL Injuries Part Editor: Timothy Edwin Hewett, PhD, FACSM Chapter 10. Biomechanics Associated with Injury: Athlete Interviews and Review of Injury Tapes Tron Krosshaug and Roald Bahr, MD, PhD Defining Injury Mechanisms Describing the Inciting Event Research Approaches to Describe the Injury Mechanisms Literature Search Athlete Interviews Video Analysis Conclusions Chapter 11. Clinical Biomechanical Studies on ACL Injury Risk Factors Laura J. Huston, MS Background Kinematic and Kinetic Differences Jump Landings Sidestep and Cutting Maneuvers Muscular Differences Altered Muscle Activation Patterns Conclusions Chapter 12. Effects of Neuromuscular Training on Lower Extremity Motion Patterns Bing Yu, PhD; and Marlene DeMaio, MD Combined Training Programs Including Plyometrics Chapter 13. Sport-Specific Injury Mechanisms Associated With Pivoting, Cutting, and Landing Mary Lloyd Ireland, MD Gender Comparisons Definitions of Mechanism of Injury Soccer Team Handball Basketball Gender Differences Conclusions Chapter 14. Effects of Muscle Firing on Neuromuscular Control and ACL Injury Timothy Edwin Hewett, PhD, FACSM; Bohdanna T. Zazulak, DPT, MS, OCS; and Gregory D. Myer, MS, CSCS Introduction Differences in EMG Activation Levels Between Males And Females Summary and Conclusions Chapter 15. Etiology and Mechanisms of ACL Injury in Alpine Skiing Bruce D. Beynnon, PhD; Carl F. Ettlinger, MSME; and Robert J. Johnson, MD The Epidemiology of Alpine Skiing Injuries ACL Injury Mechanisms Associated With Alpine Skiing Summary Chapter 16. Noncontact ACL Injuries in Dance and Skating Carol D. Teitz, MD Muscular Control Shoe-Surface Interface Center Of Gravity and Proprioception Choreography Miscellaneous What About Gymnasts? Summary Chapter 17. The Role of Biofeedback in Preventing Noncontact ACL Injuries Julie R. Steele, PhD; Bridget J. Munro, PhD The Role of Biofeedback in ACL Injury Prevention Biofeedback, Neuromuscular Activity and ACL Injury Prevention Biofeedback, Knee Joint Motion and ACL Injury Prevention The Role of Biofeedback in Preventing ACL Reinjury Future Directions for Biofeedback and ACL Injury Prevention Part IV. Hormonal and Anatomic Risk Factors and Preventive Bracing for ACL Injuries Part Editor: Sandra J. Shultz, PhD, ATC, CSCS Chapter 18. Ligament Biology and Its Relationship to Injury Forces James R. Slauterbeck, MD; John R. Hickox, MS; and Daniel M. Hardy, PhD Relationships Among ACL Injury Factors Effects of Tissue Remodeling Sex, Hormones, and ACL Injury Chapter 19. Hormonal Influences on Ligament Biology Sandra J. Shultz, PhD, ATC, CSCS Sex Hormone Profiles: Not all Menstrual Cycles Are Created Equal Sex Hormones Effects on Collagen Structure and Metabolism Sex Hormones and Knee Joint Laxity and Stiffness Menstrual Cycle and ACL Injury Summary Birth Control Hormones, Ligament Biology and ACL Injury Summary Chapter 20. Anatomical Factors in ACL Injury Risk Sandra J. Shultz, PhD, ATC, CSCS; Anh-Dung Nguyen, MS Ed, ATC; and Bruce D. Beynnon, PhD Notch Size and Width Generalized Joint Laxity Anterior Knee Laxity Anatomical Alignment Conclusions Chapter 21. Intrinsic and Extrinsic Forces Associated With ACL Injury: Can Functional Bracing Reduce the Risk of ACL Injury? Bruce D. Beynnon, PhD; and James R. Slauterbeck, MD The Biomechanics of Knee Bracing The Effectiveness of Braces in Preventing ACL, ACL Graft, and ACL-Deficient Knee Injuries Conclusion References Index About the Editors