Factors Influencing Excessive Dynamic Genu Valgum and the Effect on Post-Landing Movement Patterns: A Cross-Discipline Narrative Review.

This review summarizes the existing literature to investigate the role of excessive dynamic genu valgum (DGV) upon landing on subsequent movement performance in athletes. General systems theory and kinetic chain theory comprise the underlying theoretical frameworks, with an emphasis on regional interdependency in the context of lower-limb kinematics. Using a snowballing methodology, information was obtained from PubMed, CINAHL, Wiley Online Library, ProQuest, and Scopus databases, as well as through the utilization of Google Scholar and relevant biomechanics and movement analysis textbooks. Limitations include a paucity of research in the absence of injury and on DGV and subsequent performance post landing. Numerous factors, such as strength deficits of the predominant stabilizers of the knee in the frontal plane, fatigue, presence of dual tasks, and ingrained motor control, may influence medial knee excursion upon landing. Increased medial knee excursion during the transition from force attenuation to control is theorized to reduce the mechanical advantage of the quadriceps, impairing the efficiency of the stretch-shortening cycle for subsequent athletic movement performance. Mechanical and cognitive factors may influence knee biomechanics during landing and subsequent movement efficiency; however, the existing literature would benefit from further exploration of the differences in movement mechanics (e.g., acceleration) post landing in excessive DGV and the role of the trunk and subtalar joint on knee kinematics through the context of regional interdependency. This review is novel in investigating DGV from the perspective of movement performance rather than injury.