As a child matures and begins to walk, knock knees (the medical term is genu valgum) can develop as he or she tries to maintain balance on weakened legs. When a knock-kneed child stands up with his or her feet parallel and hip-width apart, the knees point toward each other (towards the midline). As the legs gain strength and start to mature, they generally straighten out and the condition disappears. Knock knees may continue after the age of three or four, but by age five most legs straighten.
For adults, being slightly knock kneed is a normal variation in alignment; many adults are somewhat knock kneed. This is rarely a problem, and surgery or physical therapy is seldom undertaken to correct it. However, severe knock knees in adults can lead to further problems.
What causes knock knees?
Knock knees are common, often developing as part of the childhood growth process. However, trauma or certain conditions such as rickets, bone infections, or obesity can cause knock knees.
Normal physiologic alignment in children
Normal development in children between birth and seven years of age consists of a progression from bow legs, to knock knees, to normal adult alignment. It is normal for children to have bow-legs from the time they are born until they are 18 to 24 months of age. Around this time alignment should be fairly neutral. From 24 months until 4 years of age, knock knees are normal. Between ages 4 and 7, the alignment should progress from knock knees back to a neutral position. By 7 years of age, the alignment should be the same as that in an adult.
What if you do nothing?
In children the legs usually will straighten out as the child grows. However, if a case of knock knees is severe or if it is still present at the age of seven, medical attention is needed to prevent permanent problems. Knock knees rarely lead to walking problems, but if left untreated they may contribute to early-onset arthritis. They can also lead to difficulties with self-esteem in children.
Home remedies for knock knees
• Wait and watch (children). Knock knees are common among children, and in most cases the legs will eventually straighten out. Medical treatment is seldom required.
• Use orthotics (adults). For adults with severe knock knees, orthotics—foot supports, made of foam, leather, plastic, fiberglass, graphite, or some combination, that fit in your shoes—can reduce the increased risk of exercise-related injury by correcting the structural imbalance.
How to prevent knock knees
In most cases, knock knees can’t be prevented.
When to call your doctor about knock knees
Contact your doctor if a child’s legs don’t straighten out or if a knock-kneed appearance develops in a child seven years of age or older. Adults with knock knees should consult an orthopedist or podiatrist if the condition is so pronounced that it causes pain or interferes with movement.
What your doctor will do
A careful examination will be performed to rule out conditions that tend to cause knock knees. X-rays may be taken to determine the severity of the condition. For severe knock knees, your doctor may recommend braces to be worn at night and special shoes.
Surgery may help correct knock knees after the age of 10 for girls and 11 for boys if the braces and shoes aren’t able to straighten their legs. For adults, the doctor may fit the patient with orthotic devices for the shoes to keep the feet from rolling inward excessively (pronating).