Is It Bad to Have Knobby Knees? Understanding Genu Valgum

October 2, 2025 •

5 min read

Knock knees, often referred to as knobby knees, are a normal part of development in most children, with the condition resolving on its own around age eight. However, when this inward angulation of the knees persists into adulthood, it can become a significant orthopedic concern.

Quick Summary

Having knobby knees is not inherently bad for everyone; for young children, it's typically a harmless and temporary growth stage. When the condition persists into adulthood, is severe, or causes symptoms like pain and instability, it can lead to complications such as early-onset arthritis.

Key Points

Normal for children: For most children, knobby knees (genu valgum) are a harmless and temporary stage of development, usually resolving by age eight.
Persistent cases are problematic: If knobby knees persist into adulthood, are severe, or cause pain, they can indicate a more serious orthopedic issue.
Underlying causes vary: Causes for problematic genu valgum include injury, obesity, genetic factors, and underlying bone diseases like rickets.
Complications include arthritis: If left untreated, chronic misalignment can lead to joint instability, pain in the knees, hips, and ankles, and premature osteoarthritis.
Know the red flags: Seek medical advice if knock knees are severe, asymmetrical, worsen with age, or are accompanied by pain, limping, or other concerning symptoms.
Treatment options exist: Depending on severity and cause, treatment can range from observation and physical therapy to orthotics, weight management, and, in severe cases, surgery.

What Exactly Are Knobby Knees?

Knobby knees, medically known as genu valgum, is a condition where the knees bend inward and touch or 'knock' against each other when a person stands with their ankles apart. While the appearance can be cosmetic, the underlying issue is an alignment problem where the mechanical axis of the leg shifts, placing increased pressure on specific parts of the knee joint. This misalignment is often more noticeable during certain developmental stages in children but can become a chronic issue for some individuals.

Knobby Knees in Children: A Normal Phase of Growth

Parents often worry when they notice their child's knees turning inward, but in many cases, this is a natural part of growth. Here is a typical developmental timeline:

Infancy: Most infants are born with bowlegs (genu varum) due to their position in the womb.
Toddlerhood (Ages 2-4): As children begin to walk, their legs naturally shift to a knock-kneed position, which helps with balance. The degree of knock-knee is often most apparent during this period.
Later Childhood (Ages 7-8): For the vast majority of children, the legs naturally straighten out and correct the alignment by this age, requiring no intervention.

During this normal developmental process, the condition is referred to as physiological genu valgum and is not a cause for concern. Medical attention is usually not needed unless specific red flags appear.

When Knobby Knees Become a Problem: Pathological Genu Valgum

While most children outgrow knock knees, the condition can persist or develop later in life. In these instances, it is known as pathological genu valgum and is more likely to cause complications. In adults, the constant misalignment puts excessive and uneven force on the knee joint. The following factors can cause or worsen the condition:

Genetics: Some people are born with a predisposition to this alignment.
Injury: Trauma to the growth plate during childhood or an injury to the ligaments in the knee can lead to misalignment.
Obesity: Excess body weight places additional stress on the knees, contributing to or worsening genu valgum.
Underlying Diseases: Conditions such as rickets (vitamin D deficiency) or metabolic bone disorders can affect bone growth and cause knock knees.
Arthritis: Degenerative joint diseases like osteoarthritis can cause structural changes in the knee, leading to or exacerbating a knock-kneed alignment.

Symptoms and Potential Complications

In cases where knobby knees are a problem, symptoms can range from mild to severe and may worsen over time. Possible complications include:

Pain: The uneven distribution of weight can lead to pain in the knees, ankles, feet, or hips.
Gait Issues: A visible limp or an awkward walking pattern can develop as the body compensates for the misalignment.
Instability: The abnormal joint mechanics can lead to knee instability or patellar (kneecap) maltracking.
Increased Risk of Injury: The strained ligaments and tendons around the knee can make it more susceptible to injury.
Accelerated Arthritis: The constant rubbing and pressure on one side of the knee joint can cause cartilage wear and lead to premature osteoarthritis.

What are the Red Flags?

It's important to know when to seek a medical evaluation, especially if symptoms are present. Consider consulting a doctor if you or your child exhibits any of the following:

Knock knees that are severe or appear to be worsening over time.
Only one leg is affected, or there is a significant asymmetry between the legs.
The condition is accompanied by pain, limping, or difficulty running.
Knock knees are first noticed after age 6.
The affected person has a very short stature or is significantly underweight.

Diagnosis and Treatment Options

A healthcare professional will typically perform a physical examination to diagnose genu valgum. They may measure the distance between the ankles when the knees are together (intermalleolar distance) and assess gait. For more complex cases, X-rays may be used to evaluate the bone structure and severity of the alignment.

Treatment depends on the age of the patient and the severity of the condition. While mild cases in children are typically observed, more significant or symptomatic cases require intervention. Options can include:

Observation: For most children under age 7 with a mild case, the 'wait and see' approach is standard, as it is expected to self-correct.
Physical Therapy: Exercises to strengthen the muscles around the knees, hips, and ankles can help improve joint stability and alignment.
Orthotics: Custom shoe inserts can help address foot alignment issues that may be contributing to the knee problem.
Weight Management: Reducing excess weight can decrease the stress on the knee joints, slowing the progression of damage.
Bracing: In some cases, a brace may be used to provide support, especially in adults with arthritis, but it won't correct the underlying deformity.
Surgical Intervention: For severe cases, especially those causing significant pain or dysfunction, surgery may be necessary. Procedures vary by age and include guided growth surgery for children or osteotomy for adults to realign the bones.

Knobby Knees in Perspective: A Comparison

To better understand the difference between normal developmental knock knees and more serious cases, consider the following comparison:


Feature	Normal Childhood Genu Valgum	Persistent/Pathological Genu Valgum
Onset	Ages 2-4, typically resolves by 7-8	Persists after age 7 or develops later in life
Severity	Mild to moderate, affects both legs evenly	Can be severe, asymmetrical, or progressively worsening
Symptoms	Often asymptomatic, or mild gait issues	Pain (knee, hip, ankle), limp, instability, stiffness
Underlying Cause	Natural growth pattern	Injury, disease (e.g., rickets), arthritis, obesity
Treatment	Observation, typically self-correcting	Physical therapy, orthotics, weight management, or surgery

Can It Be Prevented?

While you cannot prevent physiological genu valgum in children, taking proactive steps can help prevent pathological cases in both children and adults. Maintaining a healthy body weight reduces stress on the joints. Ensuring proper nutrition, especially adequate vitamin D and calcium, is crucial for bone health and preventing conditions like rickets. For individuals with a genetic predisposition or a history of knee injuries, strengthening exercises and avoiding high-impact activities can help protect the joints. Seeking early evaluation for any concerning symptoms is key to managing the condition effectively.

For more detailed information on genu valgum, you can consult authoritative medical sources like the Hospital for Special Surgery.

Conclusion

So, is it bad to have knobby knees? The answer is nuanced. While often a benign and temporary phase in childhood, persistent or symptomatic genu valgum in adults can lead to progressive joint damage, pain, and arthritis. The key is to understand the signs and symptoms that warrant medical attention. By addressing the root cause, whether through conservative management or surgical correction, you can protect your knee health and improve your overall quality of life.

Frequently Asked Questions

For most children, knobby knees are not serious and are a normal part of growth. However, if the condition persists into adulthood or is severe, it can become a health problem, causing pain, instability, and an increased risk of arthritis due to uneven pressure on the joint.

It is typically a concern if a child's knock knees do not correct themselves by around age seven or eight. Concerns also arise if the condition is severe, affects only one leg, or is accompanied by pain, a limp, or trouble with physical activity.

Yes, for adults with pathological genu valgum, the constant stress from the misalignment can lead to long-term pain in the knees, hips, ankles, and even the back. The uneven wear and tear on the cartilage can also lead to chronic pain from arthritis.

While exercise cannot correct the underlying skeletal alignment in adults, targeted physical therapy can strengthen the supporting muscles, improve gait, and increase joint stability, which can help manage pain and slow the progression of joint degeneration.

Yes, non-surgical options include physical therapy, weight management, and wearing special shoe inserts (orthotics) to help with foot alignment. These treatments focus on managing symptoms and protecting the joints from further damage.

Knobby knees (genu valgum) is when the knees angle inward, touching or 'knocking,' while the ankles are apart. Bowlegs (genu varum) is the opposite, where the legs curve outward, creating a gap at the knees when the ankles are together.

Physiological knobby knees in childhood cannot be prevented. However, for adults, maintaining a healthy weight, ensuring adequate nutrition (especially Vitamin D and calcium), and managing underlying conditions can help prevent the onset or progression of pathological genu valgum.