Knock Knee is a term used to describe the condition of knees when the both the knees touch each other when legs are straightened it also includes a large gap between the knees. Genu valgum is the scientific name given to knock knee, in Medical Exams of Service Selection Boards candidates are examined for knock knees and those candidates who are found with knock knee are not eligible to join the Indian Defence Forces.
To test whether you have knock knee or not you have to just stand on floor forming a "V" shape and if there is Small Gap between your knees then it's fine but if the gap is too much or your knees are touching each other then you must consult a doctor.
As shown in the picture the person P1 has knock knee as his both the knees are touching each other while the person P3 also have a deformities in his knees as the gap between his knees is quite large when they are standing making a shape of V and the person P2 have a normal Knees as his both Knees are having a small gap.
The degree of knock knee is determined by an angle called Q angle. It is 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. The Q angle for men should be less than 18 degrees with the knee in extension and less than 8 degrees with the knee in 90 degrees of flexion and for Women it should be less than 22 degrees with the knee in extension and less than 9 degrees with the knee in 90 degrees of flexion.
Knock Knee could be due Obesity (Overweight), Rickets which is caused due to deficiency of vitamin D, Osteomyelitis a bone infection or Injury to shinbone. These are some of the causes of Knock Knee amongst a wide variety of reasons.
Problems Due to Knock Knee
Generally the problems vary from person to person one of which is Difficulty in walking and at later stage it can cause knee problems such as osteoarthritis and chondromalacia if left untreated, it can also makes knees more prone to injury.
Knock Knee Treatment
As far as medical science is concerned till now there is no known cure for knock knees after childhood age. However it is claimed by some sources that Knock Knee can be treated by Yoga, Exercise and Surgery. There is a another method of placing a pillow between your knees and tie your both the feet together and another method is in which a Person can use a night brace, which is attached to a shoe or orthopedic shoe.