Weak Hip Strength Increases Dynamic Knee Valgus in Single-Leg Tasks of Collegiate Female Athletes

Clinical Scenario: Dynamic knee valgus (DKV) is a mechanical alteration in the knee that leads to increased risk of injury. Weakness of hip musculature in hip abduction (HABD), extension (HEXT), and external rotation (HER) may contribute to increased DKV in single-leg landing tasks. Focused Clinical Question: Is decreased hip strength associated with an increase in DKV during a single-leg landing task in collegiate female athletes? Summary of Key Findings: Three studies were included: One randomized control trial (RCT), one cohort study, and one case-control. All three studies found that decreases in HABD and HER strength contributed to increased DKV during single-leg landing tasks. One study also found that the hip extensors contribute to controlling hip adduction, a common factor in many mechanisms of injuries. These three studies recommended strengthening HABD, HEXT, and HER to decrease DKV and reduce the risk of injury at the knee. Clinical Bottom Line: Weak HABD, HEXT, and HER contribute to increased DKV in college female athletes, but strengthening HABD, HEXT, and HER can lead to decreases in DKV and, overall, reduce the risk of injury at the knee. Strength of Recommendation: These articles were graded with a level of evidence of III or higher, giving a grade of B strength of recommendation that weak HABD, HEXT, and HER are associated with increased DKV in collegiate female athletes.