Background and Objectives: Dynamic knee valgus (DKV) is an abnormal movement pattern visually characterized by excessive medial movement of the lower extremity during weight bearing. Knee valgus most commonly occurs during upright ground-based activities that require eccentric action of the hip extensors Differences in lower extremity kinematic components of DKV may explain the emergence of different pain problems in people who exhibit the same observed movement impairment. The perpuse of this study was to investigate lower extremity isometric strength between females who exhibit medial knee displacement during squat in compraed to control group. Methods: This cross-sectional and descriptive study was carried out on forty healthy females (control, 20 ; dynamic knee valgus, 20) with no lower-extremity injury in the past 6 months elected randomly according to inclusion criteria. Peak isometric strength of hip flexion. hip extention, hip external rotation, hip internal rotation, knee extention, knee flexion, plantarflexion, dorsiflexion, inversion and eversion were measured in kilogeram using a hand-held dynamometer. Independent t- test and Multi-variate analyses of variance were used to determine differences in demographic characteristics and strength between groups (P≤0.05). Results: The reasults showed dynamic valgus group had the less hip extention (P=0.048), hip external rotation (P=0.054) and plantarflexion strength (P=0.000) in compraed to control group. Conclusion: Hip extensor, external rotator and ankle palantarfexor weakness may predispose the body to injury by altering trunk or lower extremity kinematics, resulting in increased mechanical stresses on various joints and soft tissues. According to present results interventions focusing on improving strength of the hip and ankle may improve kinematics during dynamic activities.
