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|Classification and external resources|
Genu valgum, commonly called "knock-knee", is a condition in which the knees angle in and touch one another when the legs are straightened. Individuals with severe valgus deformities are typically unable to touch their feet together while simultaneously straightening the legs. The term originates from the Latin genu, "knee", and valgus which actually means bent outwards, but in this case, it is used to describe the distal portion of the knee joint which bends outwards and thus the proximal portion seems to be bent inwards. For citation and more information on uses of the words Valgus and Varus, please visit the internal link to -varus.
Mild genu valgum can be seen in children from ages 2 to 5, and is often corrected naturally as children grow. However, the condition may continue or worsen with age, particularly when it is the result of a disease, such as rickets or obesity. Idiopathic genu valgum is a form that is either congenital or has no known cause.
Other systemic conditions may be associated, such as Schnyder crystalline corneal dystrophy, an autosomal dominant condition frequently reported with hyperlipidemia.
People with knock knees usually also have collapsed inner arches of their feet, and their inner ankle bones are lower than their outer ankle bones. To correct knock knees, you need to work on the whole leg, especially 1. activating and developing the arches of their feet, 2. waking up the inner leg muscles (adductors), and 3. learn how to move the inner ankle bone inwards towards the outer ankle bone, and upwards towards the knee. Working with a body balance specialist like a good physio, osteopath, feldenkreis or Iyengar Yoga teacher will assist with learning how to do these corrections, and learning how to use the leg muscles properly to support the bone structures.
Adults with uncorrected genu valgum are typically prone to injury and chronic knee problems such as chondromalacia and osteoarthritis. In some cases, total knee replacement (TKR) surgery may be required later in life to relieve pain and complications resulting from severe genu valgum.
Most doctors use leg braces to move the leg back into position.
Diagnostic test 
The degree of genu valgum can be estimated by the Q angle, which is the angle formed by a line drawn from the anterior superior iliac spine through the center of the patella and a line drawn from the center of the patella to the center of the tibial tubercle. In women, the Q angle should be less than 22 degrees with the knee in extension and less than 9 degrees with the knee in 90 degrees of flexion. In men, the Q angle should be less than 18 degrees with the knee in extension and less than 8 degrees with the knee in 90 degrees of flexion. A typical Q angle is 12 degrees for men and 17 degrees for women.
See also 
- orthoped/495 at eMedicine
- 1697644537 at GPnotebook
- Genu valgum, from Duke University's Wheeless' Textbook of Orthopaedics