Abnormal force on the tibia or lower leg bone from obesity causes a slowing down or even puts a stop to bone growth in some children. When the force exceeds the maximum amount that the growth plate can handle, then bone growth on one side of the bone is affected. The natural result is a condition called Blount disease or abnormal bowing of the lower leg.
At what point this happens remains unclear. Sometimes it occurs in the young child (under the age of three). In other cases, it doesn’t show up until the teen years. How much force is too much may vary from child to child. It’s not always clear at what point a child crosses over from being overweight to being obese.
It’s likely that Blount disease is multifactorial. This means that more than one cause combined together brings it on. Studies show that race, gender, and size are all part of the mix. More studies are needed to narrow down the exact cause and sequence of biologic or mechanical events that lead to this condition.