Valgus knees refers to a condition in which the knees angle inward. It is often accompanied by inward hip rotation and a flattened foot arch. More common in women than men, valgus knee often causes no symptoms. However, people with valgus knee are at increased risk for anterior cruciate ligament injury, which involves stretching or tearing of one of the ligaments that holds the knee in normal alignment. Valgus knee also causes increased pressure on the outside compartment of the joint, which may eventually lead to knee arthritis. Strengthening the knee and hip muscles can improve a valgus knee.