What are Knock Knees?

Definition of Knock Knees

Knock knees, also known as genu valgum or valgus knees, is a postural alignment where the knees angle inwards, causing them to touch or come close while the ankles remain apart. When you stand in front of a mirror, this positioning might resemble an "X" shape from the hip to the knee in the thigh bone and from the knee to the ankle in the shinbone.

You're not alone if you've noticed this in your stance. While it's natural to feel a hint of concern or even self-consciousness, recognizing it is the first step toward empowerment. Knowledge paves the path to understanding and addressing concerns. At Activ8, we assure you that positive changes are well within reach with the right information and guidance.

knock knees posture skeletal image

Self-Assessment for Knock Knees

Wondering if you have knock knees? While medical evaluations using X-rays provide definitive answers, a simple self-assessment can give you an initial understanding of your knee alignment. Here's how you can check at home:

  1. 1
    Stand Straight: Begin by standing upright on a flat surface, ensuring your posture is straight and your feet are parallel.
  2. 2
    Position Your Feet: Bring the insides of your feet to touch each other. Ensure your heels are aligned, and there’s no gap between them.
  3. 3
    Observe in the Mirror: Using a full-length mirror, observe the alignment of your knees. In cases of knock knees: A) The knees touch or come very close while there’s still a gap between the ankles. B) In more severe cases, the knees will touch before the ankles do, even when the insides of the feet are perfectly aligned.
  4. 4
    Assess the Gap: Take note of the distance between your ankles when touching your knees. A significant gap could indicate a case of more severe knock knees.

Remember, while this self-assessment can provide insights, consulting with a professional for a comprehensive evaluation and guidance on any potential postural concerns is always best. You can schedule a free posture assessment with Activ8 Posture.

Anatomy Overview

anatomy of knock knees posture and whole body alignment

Knock knees are more than just a unique stance; they're a product of anatomical interactions of multiple joints in the leg. Diving deeper into the human anatomy provides a clearer understanding of the nuances involved with this postural alignment.

Hip Joint:

 At the heart of knock knees is the hip joint, specifically hip adduction. Hip adduction is where the thigh moves inwards towards the body's midline. Those with knock knees tend to have dominant hip adductor muscles. The main muscles involved in this action include the adductor magnus, adductor longus, adductor brevis, and gracilis. When these muscles are overly tight or overactive, it can lead to excessive hip adduction, setting the stage for the knock knees alignment.

Knee Joint:

Moving down to the knee joint, the condition involves a form of knee abduction. While "abduction" usually implies a movement away from the body's midline, in the context of knock knees, it denotes the outward movement of the lower leg in relation to the thigh. The concave angle created by the thigh bone (femur) and shinbone (tibia) indicates the degree of knee abduction.

Ankle Joint:

Finally, the ankle joint often demonstrates an inversion. In this position, the sole of the foot turns inward. Continuous weight-bearing in this alignment can lead to increased stress on the ankle and arch of the foot. The tibialis anterior and tibialis posterior are pivotal muscles that control this movement. If knock knees persist, it predisposes individuals to conditions like high arches (or flat feet when duck feet are present due to the pressure exerted on the inner arch).

The combined impact of hip adduction, knee abduction, and ankle inversion gives the characteristic knock knees stance. However, it's important to understand that this isn't merely a superficial alignment. The interaction between these joints and the muscles, tendons, and ligaments that connect them plays a pivotal role in everyday movements and overall body mechanics.

At Activ8, we emphasize the importance of a whole-body approach. While understanding the localized anatomy is crucial, seeing the bigger picture – the kinetic chain of how each part influences the other – offers deeper insights and more effective solutions. With this approach, we're better equipped to navigate the challenges and complications of conditions like knock knees.

Synonymous Posture Terms

When discussing knock knees, it's helpful to be familiar with related terms that touch upon similar anatomical deviations or describe the posture in varying ways. Here's a broad list of medical terminologies and their more colloquial counterparts:

  • Genu Valgum: The formal term for knock knees, where the knees angle inwards.
  • Valgus Knees, or Valgus Knee Stress: Another medical descriptor for knock knees, emphasizing the valgus alignment of the knees.
  • X-Legs: A colloquial term for knock knees, drawn from the 'X' shape the legs form when viewed from the front.
  • Genu Varum: The opposite condition to knock knees. It describes a posture where the knees stay wide apart.
  • Bowlegs: The common term for genu varum, inspired by the bowed appearance of the legs.
  • O-Legs: A layman's descriptor for bowlegs, referencing the 'O' shape formed by the space between the legs when standing.

Movement Matters: The Knock Knees and Gait Connection

knock knees effects the kinetic chain and causes more than knee pain

Knock knees during the loading and stance phases of gait can result from the domino effect of muscular imbalances.

Jordan, a passionate trekker, came into Activ8 Posture after sensing a disparity in her step and frequently experiencing medial knee and right S-I joint pain, especially after long hikes. Closer observation by her posture therapist shed light on an excessive valgus stress in Jordan's right knee, particularly prominent during the loading phase of her walking pattern.

Now, while this could be brushed off as merely a knee problem, the body's kinetic chain tells a more complex tale. As Jordan's foot hit the ground, the lack of stability and control from her hip adductors and weakened gluteal muscles forced her right knee inward. This inward knee movement was exacerbated by the compensatory external rotation of the same hip and eversion at the ankle.

However, the story doesn't stop there. To counteract this imbalance and continue her forward motion with stability, Jordan's left hip dropped and her pelvis rotated forward during the right stance phase, causing an even greater lateral shift in her pelvis. Additionally, the compromised foot arch and ankle pronation played into this misalignment, solidifying the knock-kneed stance further.

When Jordan was stationary, it was evident that this knock knee posture was no transient hiking issue; it had integrated into her standing posture due to the chronic adaptations her body had made to the muscular imbalances.

This all-too-common account underlines the body's profound interconnectedness. A muscle misalignment or skeletal dysfunction in the hip or foot can manifest distinctively as knock knees. Thankfully, with targeted postural therapy exercises and gait training, Jordan was on a path to rectify her knee alignment and reclaim her love for trekking without discomfort.

The Biomechanics of Knock Knees

Understanding knock knees from a biomechanical perspective provides insight into how the condition develops and impacts overall body posture and movement. Let's delve into the interplay of skeletal and muscular structures, the intricate joint movements, and the ripple effect of postural deviations caused by knock knees.

posture and movement dysfunction with uneven hips and valgus knee stress

Skeletal and Muscular Structures

Knock knees, or genu valgum, arise from a complex interplay of skeletal misalignment and muscular adaptations. This posture's biomechanical intricacies result from a combination of shortened and lengthened muscle groups and myofascial lines determined by the joint actions from the hip to the ankle.

Shortened Muscles and Myofascial Lines:

  • Adductors: Comprising the adductor magnus, longus, and brevis, these muscles draw the thighs inward, promoting hip adduction.
  • Medial Hamstring Muscles: Specifically, the semitendinosus and semimembranosus. These muscles accentuate the internal rotation and adduction of the thigh.
  • Lateral Knee Structures: Although the valgus position of the knee tends to shorten some of the lateral knee structures (such as the lateral collateral ligament, or LCL), this can also be counteracted by the lengthening effect from hip adduction.
  • Lengthened Muscles and Myofascial Lines:

  • Hip Abductors: The gluteus medius and minimus become elongated with the adducted position of the thigh. As a result, they're often weakened and less effective in countering the inward pull.
  • Lateral Structures Crossing the Hip: The adducted position at the hip can stretch and potentially weaken structures like the Tensor Fasciae Latae (TFL) and portions of the IT band that cross the hip laterally.
  • Medial Knee Structures: The knock-kneed position can lengthen many medial structures that cross the knee, including the medial collateral ligament (MCL), posterior oblique ligament, posteromedial capsule, anterior cruciate ligament, posterior cruciate ligament, semimembranosus.
  • Lateral Ankle Structures: When present, the ankle's inversion can lengthen its lateral structures, further affecting stability and alignment. This includes ligaments such as the calcaneofibular ligament and anterior talofibular ligament, along with muscles and tendons such as the peroneals.
  • Understanding the interactions and adaptations of these muscle groups and fascial lines is crucial for an effective therapeutic approach to genu valgum. Addressing the shortened and lengthened structures across all affected joints provides a holistic perspective on treatment and intervention.

    Joint Movements of Genu Valgum

    With knock knees, joint movements can be disrupted or altered, often as a result of muscle imbalances:

    • Hip Joint Adduction: The hip joints move inwards, primarily due to the dominant adductor muscles' action and the abductors' weakening.
    • Knee Joint Abduction: In response to the hips' inward movement, the knees shift inwards, even as the ankles might remain further apart.
    • Ankle Inversion: Often, as a consequence of the above joint movements, there's a tendency for the ankle to roll inwards slightly.
    • Kinematic Sequencing: This refers to the synchronized sequence of movements across the body's joints. In the context of knock knees, imbalances disrupt this sequencing, causing excessive stress on certain joints or leading to inefficient movement patterns.

    Often, knock knees result from compensatory mechanisms like increased hip stabilization through the adductors, combined with limited pelvic tilt. Sedentary lifestyles, common in modern society, further contribute to this condition, especially among the less active population, including pediatric groups.

    Postural Deviations Commonly Found with Knock Knees

    Knock knees affect the stability and mobility of the body, influencing several other postural deviations:

    • External Femur Rotation: The femur might rotate outwards due to the imbalance between the medial and lateral thigh muscles.
    • Internal Femur Rotation: Often confused with valgus knees, internal rotation of the knees (transverse plane motion) can accompany the knocking in (frontal plane motion).
    • Knee Flexion: An increased inward pressure can sometimes cause the knees to remain slightly bent, impacting gait and stance.
    • Anterior Pelvic Tilt: The strong pull of the adductors and altered hip mechanics can lead to a forward tilting of the pelvis.
    • Lumbar Lordosis (or Hyperlordosis): An anterior pelvic tilt can result in a pronounced inward curve in the lumbar spine.
    • Flat BackWhile anterior pelvic tilt should produce lordosis, or extension, in the lumbar spine, the tightness and dysfunction of the hips often are accompanied by a flat back.
    • High Arches: When the feet are straight, ankle inversion can compensate for the upper leg's inward angle and the lower leg's outward angle. A “varus” condition at the ankle compensates, resulting in high arches.
    • Flat Feet or Pronation: The inward rolling of the ankles can flatten the arches, affecting foot posture and function. This is normally the case with duck feet (i.e., feet that point out versus pointing straight).

    Recognizing these biomechanical aspects of knock knees provides a comprehensive understanding of its origin and the subsequent ripple effects on body alignment. This knowledge is a foundation for targeted therapeutic interventions and movement coaching to restore balance and harmony to the musculoskeletal system.

    What are the Symptoms of Knock Knees?

    valgus knee can cause injuries and pain

    Common Pains and Limitations

    Individuals with knock knees frequently report a range of pain, discomforts, and limitations:

    • Knee Pain: Due to the irregular lateral-to-medial stress, combined with rotational and anterior-posterior stresses, this can lead to increased susceptibility to knee injuries, degenerative knee issues, heightened stress on the medial compartment of the knee joint, ligament sprains and tears, and patellofemoral pain syndrome.
    • Hip Pain: Tight hip adductors and compromised lateral hip muscles impair hip mobility, which, in turn, causes more movement in the knee. This imbalance can result in labral tears, degenerative hip conditions, sciatica, and arthritis.
    • Ankle Pain: The odd angling of the shinbone affects ankle function, leading to inversion sprains, eversion injuries, Achilles tendon strains and tears, and restricted dorsiflexion.
    • Foot Pain: Knock knees can cause uneven weight distribution across the foot, leading to conditions like plantar fasciitis, bunions, flat feet, over supination, Morton's neuroma, and fifth metatarsal stress fractures.
    • Gait Abnormalities: The condition can lead to an irregular walking pattern, increasing muscle imbalances, and bodily discomforts.
    • Balance Issues: The altered alignment can compromise body balance, particularly during dynamic activities or on uneven terrains.
    • Decreased Mobility: The misalignment can restrict knee and hip joint motions, limiting movements like squats, jumps, and pelvic and hip rotation on your golf swing.
    • Reduced Athletic Performance: The condition can hamper balance, stability, physical prowess, and power.

    Long-Term Risks and Issues

    Knock knees, if not appropriately addressed, can have cascading effects on the body, leading to various complications over time. The immediate concerns lie within the leg, but the repercussions often ripple outwards, affecting other body parts and overall physiological health.

    Localized Concerns:
    • Osteoarthritis: Persistent knock knees can increase the wear and tear on the inner knee, leading to early-onset osteoarthritis. This degenerative condition reduces the cushioning between bones, causing chronic pain and limiting joint movement.
    • Severe Knee Pain: As knock knees place excessive stress on the medial knee, pain can become a constant companion, significantly hampering mobility and daily activities.
    • Ligamentous Issues: The altered knee alignment can strain the knee ligaments, particularly the medial collateral ligament, increasing the risk of sprains and instability.
    • Difficulty Walking: As the condition worsens, the abnormal alignment can make walking challenging, and in extreme cases, individuals might need knee braces, assistance, or adaptive devices.
    Extended Musculoskeletal Impacts:
    • Hip and Pelvic Imbalances: The compensatory mechanisms in knock knees can cause the hips and pelvis to misalign, leading to hip pain, labral tears, or even sacroiliac joint dysfunction (SI joint pain).
    • Ankles and Feet: The knock-kneed alignment can alter the ankle and foot biomechanics. This may lead to flat feet, excessive pronation, and increased vulnerability to ankle sprains.
    • Lower Back Pain: The chain reaction from knock knees often reaches the lumbar spine. As the hips and pelvis tilt, they can strain the lower back muscles and ligaments, potentially causing chronic back pain and lumbar disc issues.
    Broader Physiological Issues:
    • Circulatory Concerns: Chronic pain and reduced mobility might limit physical activity, potentially leading to circulatory issues like varicose veins or deep vein thrombosis.
    • Mental Health Impacts: Chronic pain and mobility restrictions can have psychological effects, including increased risk of depression, anxiety, and reduced overall well-being.
    • Postural Adaptations: The body might develop further poor posture deviations in response to knock knees, which can affect the spine, shoulders, and neck.

    Understanding these potential long-term risks underscores the importance of early intervention and holistic treatment. Addressing knock knees is not just about straightening the legs but ensuring the entire body functions harmoniously, optimizing overall health and quality of life.

    What Causes Knock Knees?

    Knock knees often result from a complex interplay of multiple factors. While some reasons are innate, others are environmental or behaviorally influenced. Let’s delve deeper into these causes, understanding their intricacies and how they shape the knee's alignment.

    Muscular Imbalances

    Sedentary Lifestyles: Prolonged periods of sitting, a sign of modern life, can lead to tightening of the hip flexors and weakening of the gluteal muscles. Tight hip flexors pull the pelvis forward, leading to anterior pelvic tilt. This shift can force the knees inward as a compensatory mechanism to maintain balance and posture.

    Hip Adductors as Stabilizers: The adductor muscles, especially those with pelvic girdle instability, may overcompensate by becoming overly active. Pulling the thighs inward aims to provide added stability, inadvertently pushing the knees closer together.

    Developmental Patterns

    Normal Growth in Youth: It's not uncommon for toddlers and young children to exhibit knock knees as a natural growth phase. This physiological genu valgum often corrects itself by ages 6 or 7.

    Developmental Valgus Stress: A child’s legs may experience excessive inward knee stress during their growth beyond what is typical. This could be due to a combination of factors, from genetics to external pressures.

    Late Onset: While rarer, knock knees can develop in older children and adults due to various reasons, such as injury or specific health conditions.

    Nutritional Deficiencies

    Rickets: A direct consequence of deficiencies in vitamin D and calciumrickets softens and weakens the bones in children. The body's weight on these weakened bones can force the knees to bow inward, leading to knocked knees.

    Structural and Physical Issues

    Inherent Bone Abnormalities: Some individuals might be born with bone structures predisposing them to knock knees. This could be due to genetic factors, family history, or prenatal influences.

    Obesity: Carrying excessive weight amplifies the stress on the knee joints. The increased load can exacerbate the inward bending of the knees, particularly in individuals already prone to muscle imbalances. The ensuing muscle imbalances, in turn, can result in low back, hip, knee, ankle, and foot issues.

    Trauma: Injuries, especially during formative years, can disrupt normal growth patterns of the knee. Damage to the growth plate or other essential components can lead to a misalignment, resulting in knocked knees.

    In understanding the causes of knock knees, it becomes evident that prevention and management are multifaceted, requiring a keen eye on both lifestyle choices and inherent factors.

    Posture Terms Related to Knock Knees

    • Genu Varum (Bowlegs): The antithesis to knock knees where the knees remain apart while the lower legs angle out. (Also referred to as bowlegged, bow legs, varus knees, O-legs)
    • Osteotomy: A surgical procedure to correct a bone malalignment.
    • Orthotics: Custom-made shoe inserts designed to realign and stabilize foot and ankle bones.


    Knock knees are more than just a superficial postural concern; they are intricately tied to a web of muscular and skeletal interactions that, if left unaddressed, can lead to many musculoskeletal challenges. The roots of the issue often stem from muscular imbalances, sedentary lifestyles, and even developmental factors. Holistic approaches, like the posture therapy offered at Activ8 Posture, delve deep into these root causes, ensuring symptomatic relief and a comprehensive, whole-body correction. Understanding and addressing knock knees at the right time can significantly enhance one's quality of life. Taking that proactive step towards understanding and potentially treating the condition can pave the way for better knee alignment, pain relief, improved mobility, and overall well-being.

    Not sure where to start?

    Schedule your FREE Consultation & Postural Assessment today!

    Frequently Asked Questions

    How is knock knees related to a child’s development?

    Knock knees, or genu valgum, are common during a child's development, especially between the ages of 3 and 5. It's a natural phase where the legs undergo changes to achieve a mature alignment. For many children, this alignment corrects itself as they grow. However, in some cases, if the condition persists or worsens, it may indicate other underlying issues.

    When should parents be concerned about knock knees?

    While some degree of knock knees is normal in growing children, parents should be attentive if:

    • The condition appears asymmetric, meaning one knee seems more affected than the other.
    • Knock knees persist beyond the age of 7 or 8.
    • The child complains of pain or discomfort in the knees or surrounding areas.
    • There are signs of difficulty in walking or an unusual gait. Consulting a pediatric orthopedic specialist or orthopedic surgeon is crucial if any of these symptoms are observed.

    How is knock knee diagnosed?

    Knock knee is typically diagnosed through a physical examination. The doctor may observe the child's walking pattern, measure the distance between the ankles when the knees are touching, and check for any signs of discomfort or pain. In some cases, X-rays or other imaging tests might be recommended to get a clearer view of the knee alignment and rule out other potential issues.

    Are knock knees normal?

    Yes, to an extent. Many children naturally exhibit knock knees between the ages of 3 and 5 as a part of their developmental process (after having a natural bow leg). However, the condition usually corrects itself as they approach adolescence. If knock knees persist or seem severe, it might indicate other underlying issues.

    How do you fix knock knees?

    Treatment for knock knees varies depending on the cause and severity. The condition might correct itself over time in mild cases, especially in children. In most cases, whole-body postural therapy, such as what we offer at Activ8 Posture, can help reverse or improve valgus stress. More traditional remedies may include:

    • Orthopedic shoes or inserts may be recommended.
    • Physical therapy can help address muscular imbalances and improve alignment.
    • Weight management can be crucial if obesity is exacerbating the condition.
    • In extreme cases, surgical intervention might be considered. It's vital to consult a medical professional, such as a pediatric orthopedic or orthopedic surgeon, for an accurate diagnosis and tailored treatment plan.

    Read More About Posture Terms:

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