My daughter has been diagnosed with Blount disease. The doctor tells me this is linked with obesity. She is overweight but she only has this condition in the right leg. Wouldn’t it be in both legs if it was caused by a weight problem?

Blount disease is a condition of bowlegs that’s more-than-normal. Obesity has been linked with this condition. It is thought that the extra load on growing bones makes the normal curvature of the lower legs even worse.

It does make sense to think that if obesity is the problem, it should cause similar changes on both sides. But scientists have discovered that the mechanical load contributing to these changes may not be the same from side to side.

The angle of the bones and degree of curvature already present are extra factors. Many children are not the same from side to side. A few develop greater bowing on one side compared to the other. With the added factor of obesity, the bone deformity increases.

Too much pressure on the inside edge of the tibia (lower leg) can cause the bone to stop growing. When only one side of the tibia stops growing, there are abnormal changes in bone alignment. The result can be this curvature or bowing of the bone on one side.