Pediatric Bowed Legs
Bowed legs are the result of one or both legs curving outward, as in the shape of a bow.
Very common in toddlers (age 1 to 3 years*), bowed legs result in a distinct space between the lower legs and the knees, due to the legs bending outward. Bowed legs cause walking to be difficult and often exaggerates the appearance of the curved legs. Adolescents (age to 10 to 19 years**) can also develop bowed legs, but in many cases, this is related to significant body weight.
Bowed legs can occur due to a variety of reasons including:
- Achondroplasia – the most common type of dwarfism, this is when a child has severely shortened arms and legs (which are often bowed) and a normal-sized torso. This is typically an inherited condition, but can occur due to a spontaneous mutation while in the mother’s womb.
- Bone tumors or bone infections – can cause distortions in the bones, creating a bowed appearance.
- Blount’s disease – occurs in toddlers and adolescents and causes an abnormality in the upper shin bone’s growth plate (area of growing tissue at the end of long bones), which impacts the length and shape of the adult bone.
- Fracture – can cause bowing if a broken bone doesn’t heal properly or grows at a slower rate than a non-fractured bone.
- Physiologic genu varum – describes the naturally occurring bowing that can appear anytime from infancy (birth to 1 year***) to adulthood. It can occur unilaterally (on one side) or bilaterally (on both sides). A child’s legs will typically improve between age 15 to 18 months and straighten out by age 3. A unilateral bowing may be due to functional limb-length discrepancy (legs aren’t the same length) or it can run in families.
- Rickets – causes bone deformities due to vitamin D, calcium and phosphorus deficiencies. Rickets can also be caused by an inherited genetic abnormality that causes the body to absorb vitamin D incorrectly.
- Weight – can cause the legs to bow due to heavy pressure.
The main symptom of bowed legs is the angled, “bowed” appearance. Other symptoms include:
- Joint stiffness
- Knee or hip pain
- Problems walking or with a limb
*Age of toddlers as defined by the Centers for Disease Control (CDC).
**Age of adolescents as defined by the World Health Organization (WHO).
***Age of infants as defined by the World Health Organization (WHO).