Current Concepts in Hip and Core Assessment to Reduce the Risk of ACL Injury

Background: Hip and trunk ("core") muscle dysfunction has emerged as a modifiable contributor to lower-limb biomechanics linked with non-contact anterior cruciate ligament (ACL) injuries. Clinicians increasingly target core stability and control during injury-prevention screening and post-operative rehabilitation programs; however, the literature lacks a focused synthesis of core-directed strategies for ACL injury mitigation. The purpose of this current concepts review is to synthesize current evidence on hip- and core-focused assessment and rehabilitation strategies that may mitigate ACL injury risk. Design: Current Concepts Review. Methods: A narrative search of PubMed and Google Scholar (January 2000 - April 2025) identified biomechanical, prospective, interventional, and return-to-sport studies examining relationships between hip and/or trunk muscle function and ACL injury risk or recovery. Key findings were organized into (1) injury mechanisms, (2) screening and return-to-play (RTP) tests, and (3) preventive and rehabilitative interventions, with special attention to sex-specific evidence. Results: Prospective and biomechanical studies consistently show that reduced hip abduction/extension strength and diminished trunk neuromuscular control predict dynamic knee valgus and elevated ACL strain. Functional assessments such as the single-leg step-down, Y-Balance, modified Star Excursion test, hop symmetry, and muscular assessment via belt-stabilized hand-held dynamometry-reliably identify high-risk athletes and persistently impaired post-ACLR patients. Multi-component neuromuscular programs emphasizing hip and core strengthening lower overall knee-ligament injury rates by 20-60 % in youth cohorts, with larger effects in females. Early incorporation of hip/trunk exercises during rehabilitation post ACLR contributes to improved kinematics, hop performance, and patient-reported outcomes, although standardized parameters remain undefined. Conclusion: Evidence supports routine integration of hip and trunk assessment and strengthening into ACL injury-mitigation, rehabilitation, and RTP decision-making protocols. Future research should refine trunk-specific evaluation tools and establish optimal exercise dosing across sexes and competition levels. Level of Evidence: 5.