Understanding Lower Limb Alignment in Children: What’s Normal and When to Worry

Understanding Lower Limb Alignment in Children: What’s Normal and When to Worry

As an Orthopaedic surgeon, one of the most common concerns I hear from parents is about the alignment of their child’s legs. Whether it's knock knees (genu valgum), bow legs (genu varum), or flat feet, these variations can cause significant anxiety. But the truth is, many of these alignment patterns are completely normal parts of a child’s development — and they usually correct themselves over time without the need for braces, special shoes, physiotherapy, or surgical intervention.

The Natural Evolution of Lower Limb Alignment

Children's legs go through several predictable stages as they grow:

• Birth to 18 Months: Most babies are born with bow legs (genu varum). This is due to their curled-up position in the womb and is completely normal.
• 18 Months to 3 Years: As toddlers begin to walk, their legs usually straighten out. By around age 2 to 3, the legs often shift into a knock-kneed (genu valgum) appearance.
• 3 to 7 Years: Knock knees typically peak around age 4, after which the legs gradually realign to a more neutral position. By age 7 or 8, most children will have the adult alignment that they will maintain into adolescence and adulthood.

This entire process is called physiological alignment, and it's part of normal musculoskeletal growth. It is symmetric, painless, and does not affect function.

When Should Parents Be Concerned?

There are certain situations where further assessment may be required:

• Asymmetry: If one leg is noticeably more curved or straighter than the other.
• Persistent deformity: If bowing or knock knees persist beyond the normal age range:
  • Bow legs past age 2.5–3 years
  • Knock knees that are pronounced after age 7–8 years
• Associated symptoms: Pain, limping, or difficulty walking.
• Underlying conditions: Family history of skeletal dysplasias, or signs of nutritional issues (e.g., vitamin D deficiency leading to rickets).
• Unusual patterns: Very severe deformities or those worsening over time, particularly if there is a history of trauma or infection.

In these cases, an orthopaedic evaluation is important to rule out conditions such as Blount’s disease, rickets, or other pathological causes.

Does Physiotherapy or Braces Help?

A common misconception is that physiotherapy, special shoes, orthotics, or bracing can “fix” normal leg alignment. However, evidence does not support this.

Studies consistently show that neither physiotherapy nor bracing changes the natural course of physiological limb alignment.

In children with normal development and physiological patterns, the alignment will improve without intervention. Bracing and therapy may not only be ineffective, but they can also cause unnecessary discomfort, anxiety, and financial burden for families.

In fact, multiple orthopaedic guidelines — including those from the American Academy of Orthopaedic Surgeons (AAOS) and Paediatric Orthopaedic Society of North America (POSNA) — recommend observation only for children with symmetrical, painless, age-appropriate limb alignment.

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What About Flat Feet?

Much like leg alignment, flat feet in young children are also usually physiological. Most children under 6 will have flat feet due to a fat pad in the arch, and it typically resolves as the arch develops. Insoles or orthotics are rarely needed unless there is pain or functional limitation.

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Takeaway for Parents

✅ Bow legs in toddlers? Normal.

✅ Knock knees in preschoolers? Also normal.

✅ Braces and physio? Not needed in the vast majority of cases.

If you're ever unsure, a quick consultation with your orthopaedic specialist can provide clarity and peace of mind. Most importantly, trust in the body’s remarkable ability to grow, adapt, and align naturally over time.

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Need Reassurance or a Professional Opinion?
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Our clinic is always here to guide you. We’re passionate about supporting children and their families through every stage of healthy musculoskeletal development.

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