Why do my knees face inwards? Understanding knock knees and inward rotation

Did you know that knock knees, or genu valgum, is a common occurrence in children aged 2 to 4 and often corrects itself by age 7? We explore the various factors and conditions that answer the question: Why do my knees face inwards?

Quick Summary

Knees that face inward can be the result of normal childhood development, musculoskeletal imbalances in the hips and legs, or underlying medical conditions like rickets. Identifying the specific cause is the first step toward effective management and treatment.

Key Points

• Developmental Stage: Inward-facing knees are often a normal part of childhood development, peaking around age 4 and self-correcting by age 7 or 8.

• Muscle Imbalances: Weak hip abductor muscles and tight hip adductors can cause the knees to buckle inward, especially during movement.

• Foot Posture: Overpronation (flat feet) can lead to a chain reaction of internal rotation up the leg, affecting knee alignment.

• Medical Causes: Conditions like rickets, arthritis, and skeletal issues can cause pathological genu valgum, requiring medical intervention.

• Treatment Varies: Options range from strengthening exercises and physical therapy to orthotics or, in severe cases, surgical correction.

• Professional Guidance: If inward knees cause pain, affect only one leg, or persist past childhood, consult a doctor for a proper diagnosis.

Causes Behind Inward-Facing Knees (Genu Valgum)

Inward-facing knees, clinically known as genu valgum, can stem from a variety of factors. While many cases in young children are a normal part of developmental growth and resolve on their own, persistence into adulthood or a late onset may indicate an underlying issue. Understanding the root cause is crucial for determining the right course of action.

1. Normal Developmental Growth

For many young children, inward-pointing knees are a temporary stage. Infants are often bow-legged due to their position in the womb. As they grow and start walking (around 12-18 months), their legs begin to straighten. The knees may then start to angle inward, peaking around ages 3 to 4, before naturally straightening out again by age 7 or 8. This is referred to as physiological genu valgum and typically requires no treatment.

2. Musculoskeletal Imbalances and Weakness

A common culprit for inward-facing knees in both children and adults is an imbalance in the musculature of the hips and legs.

• Weak Hip Abductors and External Rotators: These muscles, located on the outer part of the hips, are responsible for moving the legs away from the body's midline and rotating the legs outward. If they are weak, the knees may collapse inward, especially during weight-bearing activities like walking or squatting.
• Tight Hip Adductors and Internal Rotators: Muscles on the inner thighs can become tight, pulling the knees inward. Combined with weak external rotators, this can create a muscular imbalance that leads to inward knee alignment.

3. Foot and Ankle Issues

Sometimes, the issue originates lower in the leg and affects the knee's position as a compensatory mechanism.

• Flat Feet (Pronation): If the arch of the foot collapses and the foot rolls inward (overpronation), it can cause a chain reaction up the leg, rotating the tibia and femur and leading to inward knee alignment.
• In-Toeing (Pigeon-Toed): This condition can stem from an inward rotation of the thigh bone (femoral anteversion) or shin bone (internal tibial torsion). While the feet point inward, the knees can also be affected, though sometimes the knees appear to face forward while the feet turn in.

4. Underlying Medical Conditions

In less common but more severe cases, inward knees can be caused by underlying health problems. These are considered pathological and warrant medical attention.

• Rickets: A bone-softening disease caused by a severe deficiency of vitamin D, calcium, or phosphate. It interferes with proper bone mineralization and can cause skeletal deformities.
• Osteomyelitis: A bacterial infection in the bone that can damage the growth plate and disrupt bone growth.
• Skeletal Dysplasias: Inherited disorders affecting bone and cartilage growth.
• Arthritis: In adults, severe arthritis in the knee joint can lead to gradual deformity and malalignment.
• Bone Tumors: Rarely, benign tumors can affect bone growth.

5. Other Factors

• Injury or Trauma: A healed fracture near the knee's growth plate can cause asymmetrical growth and lead to one-sided (unilateral) genu valgum.
• Obesity: Carrying excess weight puts additional stress on the knee joints, which can exacerbate or contribute to the development of inward knees.
• Genetics: A family history of genu valgum suggests a genetic predisposition to the condition.

Comparison: Physiological vs. Pathological Knock Knees

Feature	Physiological Knock Knees	Pathological Knock Knees
Onset	Childhood, typically between ages 2 and 4	Late childhood, adolescence, or adulthood
Symmetry	Usually bilateral and symmetrical	Can be unilateral (one leg) or bilateral
Progression	Gradually improves and resolves naturally	Worsens over time or does not improve
Severity	Mild to moderate	Severe, causes pain, instability, or functional issues
Associated Symptoms	Usually none	Pain, difficulty walking or running, gait abnormalities
Underlying Cause	Normal developmental stage	Medical condition (rickets, arthritis), injury, or genetic factor

Diagnosis and When to Seek Medical Advice

For persistent or late-onset cases, a doctor or orthopedic specialist can perform a physical examination to assess the alignment of the knees, hips, and ankles. They may also use imaging tests like X-rays to check the bone structure and determine the severity of the malalignment.

You should see a healthcare professional if:

• The condition is present in only one leg.
• The inward-facing knees cause pain or difficulty with walking or running.
• It develops or worsens after age 6 or 7.
• There is a noticeable difference in the leg length.
• You suspect an underlying medical condition.

Corrective Treatments and Exercises

Treatment for genu valgum depends heavily on the cause and severity. For many, a non-surgical approach is sufficient.

Exercises to Strengthen and Stretch Key Muscles

Targeting muscle imbalances is a core component of physical therapy for inward knees. Exercises focus on strengthening the hip abductors and external rotators while stretching the hip adductors.

1. Clamshells: Lie on your side with knees bent. Keeping your feet together, raise your top knee away from the bottom knee. This strengthens the hip abductors.
2. Side-Lying Leg Lifts: Lie on your side with legs straight. Raise your top leg toward the ceiling and lower it slowly.
3. Resistance Band Squats: Place a resistance band around your legs just above the knees. During squats, push your knees outward against the band to activate your hip abductors and external rotators.
4. Butterfly Stretch: Sit with the soles of your feet together. Use your elbows to gently push your knees toward the floor to stretch the adductors.

Other Conservative Treatments

• Physical Therapy: A physical therapist can create a personalized plan to improve strength, flexibility, gait, and posture.
• Orthotics: Special shoe inserts can correct foot overpronation, which may improve overall leg alignment.
• Bracing: While no longer commonly used for physiological genu valgum in children, braces may be recommended in certain cases.
• Weight Management: If obesity is a factor, losing weight can significantly reduce the stress on the knee joints.

Surgical Interventions

In severe cases that do not respond to conservative treatments or in cases of persistent pathological genu valgum, a surgical approach may be necessary.

• Guided Growth Surgery: For children still growing, a surgeon may place small metal plates on the inside of the knees to slow growth on that side, allowing the outer side to catch up.
• Osteotomy: This procedure, typically for adolescents and adults, involves cutting and realigning the bone either above or below the knee to correct the angle.
• Knee Replacement: In severe cases of arthritis caused by long-term misalignment, a full or partial knee replacement may be performed.

Conclusion

Understanding why your knees face inwards involves considering a spectrum of possibilities, from normal childhood development to underlying musculoskeletal or medical issues. For most children, it's a transient phase, but persistent problems should be evaluated by a healthcare professional. Whether through targeted exercises to correct muscle imbalances or more advanced medical interventions, there are effective strategies for managing inward-facing knees and preventing future complications like chronic pain or arthritis.

For more detailed information and specialized advice on orthopedic conditions, consider consulting resources from reputable institutions like the Hospital for Special Surgery. Hospital for Special Surgery

Frequently Asked Questions

Is it normal for a child's knees to face inwards?

Yes, it is considered a normal phase of development for many children between the ages of 2 and 4. This physiological genu valgum usually corrects itself naturally as the child grows, typically by age 7 or 8.

Can muscle weakness cause my knees to turn inwards?

Yes, muscle imbalances are a common cause. Specifically, weakness in the hip abductor and external rotator muscles can lead to inward knee movement, especially during activities like walking or squatting.

What is the difference between physiological and pathological knock knees?

Physiological knock knees are a normal developmental stage in children that resolves on its own. Pathological knock knees are caused by an underlying medical condition, can be more severe, and may not resolve without intervention.

Can exercising help with inward-facing knees?

Yes, specific exercises can be very effective. Strengthening the hip abductors (muscles on the outer hip) and stretching the hip adductors (inner thigh muscles) can help improve alignment. A physical therapist can guide you with the best exercises.

Does carrying excess weight affect my knee alignment?

Yes, obesity can place additional stress on the knees, contributing to or worsening genu valgum. Weight management is often a recommended part of a treatment plan.

What medical conditions can cause inward-facing knees?

Inward-facing knees can be caused by conditions such as Rickets (due to vitamin D deficiency), arthritis, bone infections, or skeletal growth disorders. These are considered more serious and require a medical diagnosis.

When should I see a doctor for my inward-facing knees?

It is advisable to see a doctor if the condition causes pain, affects only one leg, worsens over time, or is present in a child older than 7 or 8. A professional evaluation can rule out underlying issues.