CHAPTER 17 Preventing Injury to the Anterior Cruciate Ligament Timothy E. Hewett, PhD Kim M. Yearout, PT, BS Robert C. Manske, DPT, MPT, MEd, SCS, ATC, CSCS Epidemiology: Incidence and Prevalence Anatomy Overview Anterior Cruciate Ligament Posterior Cruciate Ligament Mechanism of Injury Intrinsic Factors Q-angle Notch Size Joint Laxity Hormonal Factors Extrinsic Factors Muscular Strength and Activation Patterns Muscular Activation and Recruitment Patterns Postural Considerations Landing and Jumping Characteristics Programs Designed for the Prevention of ACL Injury Dynamic Neuromuscular Analysis Training Rationale Dynamic Neuromuscular Analysis Training Protocol Summary CHAPTER OUTLINE 319