Bowed Legs (Genu Varum) in Babies & Toddlers

Content reviewed against published AAP, NIH, Mayo Clinic guidelines

Editorial policy

Last reviewed:

Bowed legs (genu varum) — where the knees curve outward when standing with feet together — are a normal part of development in babies and toddlers. Almost all babies are born with some degree of bowing due to their folded position in the womb. This typically straightens by age 18-24 months and may even transition to mild knock-knees by age 3-4. Persistent, worsening, or asymmetric bowing may need evaluation.

Key takeaways

  • Bowed legs (genu varum) — where the knees curve outward when standing with feet together — are a normal part of development in babies and toddlers.
  • Most common cause: Physiologic bowing (normal developmental variant)
  • Emergency: Sudden onset limb deformity after injury
  • Home care: Reassurance: physiologic bowing is normal and resolves without treatment in most children

Possible Causes

Physiologic bowing (normal developmental variant)common
Normal intrauterine positioning effectcommon
Blount disease (tibia vara — abnormal growth plate)uncommon
Rickets (vitamin D deficiency)uncommon
Skeletal dysplasia (achondroplasia and other conditions)rare
Metabolic bone diseaserare
Previous fracture with growth disturbancerare

When to Seek Help

Emergency — Call 911 or go to ER:

  • Sudden onset limb deformity after injury

Urgent — See doctor today:

  • Severe progressive bowing with pain or functional limitation
  • Bowing with signs of rickets (swollen wrists, poor growth, seizures from low calcium)

Same-day appointment:

  • Bowing that is clearly worsening over time (take photos to document)
  • Asymmetric bowing (one leg more curved than the other)
  • Bowing persisting or worsening after age 2
  • Bowing with lateral thrust of knee during walking

Monitor at home:

  • Symmetric mild-moderate bowing in a child under 2 (physiologic)
  • Bowing that is gradually improving over time
  • Known physiologic bowing with scheduled follow-up
  • Mild bowing in new walker (under 18 months) that is stable

By Age

0-2 months

Normal: All newborns have bowed legs from intrauterine positioning. This is completely normal and expected. Legs may appear quite curved.

Worry if: Very severe bowing present at birth (skeletal dysplasia concern). Asymmetric bowing (one side much more than other). Short limbs disproportionate to body.

2-6 months

Normal: Bowing remains normal and expected. Legs may still appear significantly curved when baby is held upright.

Worry if: Progressive worsening of bowing. Asymmetric bowing. Signs of rickets (widened wrists, delayed fontanelle closure, poor growth).

6-12 months

Normal: Bowing should begin to gradually improve. Mild to moderate symmetrical bowing is still normal at this age. As baby begins to stand, bowing becomes more noticeable but is expected.

Worry if: Bowing that appears to be worsening rather than improving. Asymmetric bowing. Bowing with wrist widening or bony swelling (rickets). Bowing with poor growth or failure to thrive.

1-3 years

Normal: Physiologic bowing typically resolves by 18-24 months. Slight bowing at 12-18 months is still normal. By age 2-3, legs should be straight or beginning slight knock-knee pattern.

Worry if: Bowing worsening after 18 months (Blount disease concern). Severe bowing affecting walking. Asymmetric bowing. Bowing persisting beyond age 2-3 years. Pain with bowing. Short stature with bowing.

Home Care

  • Reassurance: physiologic bowing is normal and resolves without treatment in most children
  • Do NOT use braces, special shoes, or corrective devices for normal physiologic bowing — they do not help
  • Take periodic photos (every 2-3 months) from the same angle to document improvement or changes
  • Ensure adequate vitamin D intake (400 IU daily for all breastfed infants, as per AAP)
  • Provide a diet with adequate calcium for bone health
  • Allow normal activity — physiologic bowing does not limit play or development
  • Ensure baby/toddler received vitamin D supplementation from birth if breastfed
  • If concerned about progression: measure the gap between knees when ankles are touching (intercondylar distance) over time

Frequently asked questions

What causes bowed legs (genu varum)?
Physiologic bowing (normal developmental variant) (common); Normal intrauterine positioning effect (common); Blount disease (tibia vara — abnormal growth plate) (uncommon); Rickets (vitamin D deficiency) (uncommon); Skeletal dysplasia (achondroplasia and other conditions) (rare); Metabolic bone disease (rare); Previous fracture with growth disturbance (rare)
When is this an emergency?
Sudden onset limb deformity after injury
What can I do at home?
Reassurance: physiologic bowing is normal and resolves without treatment in most children. Do NOT use braces, special shoes, or corrective devices for normal physiologic bowing — they do not help. Take periodic photos (every 2-3 months) from the same angle to document improvement or changes. Ensure adequate vitamin D intake (400 IU daily for all breastfed infants, as per AAP). Provide a diet with adequate calcium for bone health. Allow normal activity — physiologic bowing does not limit play or development. Ensure baby/toddler received vitamin D supplementation from birth if breastfed. If concerned about progression: measure the gap between knees when ankles are touching (intercondylar distance) over time
When should I call the doctor?
Bowing that is clearly worsening over time (take photos to document). Asymmetric bowing (one leg more curved than the other). Bowing persisting or worsening after age 2. Bowing with lateral thrust of knee during walking

Sources

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources

Related Symptoms

Bottom line

Most cases of bowed legs (genu varum) in babies are not emergencies. However, seek immediate care if sudden onset limb deformity after injury.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.