What are Bow Legs?

What are Bow Legs?

Bow legs (genu varum) is a condition where the child’s legs curve outward at the knees, even when they are standing with their feet and ankles together. Being bow legged is quite common in babies due to the tight quarters they experience in the uterus.

Most children with bow legs outgrow the condition after 18 to 24 months. If bow legs remain after two years of age, especially if there is discomfort or a limp when walking, corrective nonsurgical treatments are available, although surgical treatments may be needed.

Signs & Symptoms of Bow Legs


The definitive sign of bow legs is the “bowing” or outward curving of the knees when the child stands with the ankles together. There is typically a gap between the lower legs and the knees.

Other signs and symptoms of bow legs can include:

  • Both legs have the same outward curve
  • Toes point inward
  • Frequent tripping or clumsiness

If bowed legs continue after two years of age, there may be a bow leg deformity. Signs and symptoms of this condition can include:

  • Hip or knee pain
  • Difficulty walking or running
  • Reduced range of hip motion
  • Instability in the knees

If you suspect your child has a bow leg deformity, consult your pediatrician for a physical examination and to learn about the available treatment options.

What Causes Bow Legs?


If your toddler hasn’t outgrown their bow legs after two years, there may be an underlying cause. Conditions that can cause bow legs include:

  • Blount’s disease, a growth disorder where the growth plates around one or both knees develop abnormally. In young children, the shinbone (tibia) is usually affected, while in teens it can be both the shinbone and the thighbone (femur). Blount’s disease is the most common cause of bow legs and can worsen over time, so an early diagnosis is important.
  • Rickets, caused by a vitamin D or calcium deficiency. The lack of these nutrients can weaken a child’s bones, causing the legs to bow.
  • Dwarfism, which can be caused by achondroplasia, a bone disorder that can cause bow legs.
  • Paget’s disease of bone, a chronic disorder that interferes with the replacement of old bone tissue with new bone tissue. The condition can cause bone deformities in leg bones, resulting in bow legs.
  • Abnormal bone development, including bone dysplasia and irregular bone growth due to improperly healed fractures.

Risk Factors for Bow Legs

Risk Factors

Many babies are born with bow legs because of their folded position in the womb. In addition to Blount’s disease and other medical causes listed above, some additional risk factors can cause bow leggedness beyond the age of 2 years old.

Additional risk factors for bow legs may include:

  • Early-walkers. A child walking before 11 months can increase the risk for Blount’s disease and, consequently, bow legs
  • Childhood obesity. Excessive weight can place pressure on the joints, resulting in conditions that lead to bow legs
  • Genetics. Having a family member with bow legs may increase the risk
Get Care

Trust NewYork-Presbyterian for Bow Legs Care

A baby with bow legs is completely normal, and bow legs are often part of their development. But if the condition doesn’t straighten out on its own after 24 months, a medical evaluation is recommended to detect a medical cause, such as Blount’s disease. The pediatricians at NewYork-Presbyterian can provide an expert diagnosis and treatment options, so your child can avoid any future complications.

If you are concerned about your child’s bow legs, reach out to NewYork-Presbyterian for a pediatric consultation.