Tag: overpronation

Supination Resistance

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Supination Resistance is a concept of determining the force needed to supinate the foot. This is considered important in foot orthotic prescribing as it is helpful to determine how much force if needed from the foot orthotic if the foot is overpronating.

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Supination resistance refers to the amount of force required to supinate (invert) the foot around the subtalar joint during gait or clinical testing. It’s a key concept in biomechanics and podiatry, because it helps clinicians understand how easily or how much effort it takes for a person’s foot to resupinate during walking or running. Normally, after the foot pronates during stance phase (to absorb shock and adapt to the ground), it needs to resupinate for effective propulsion. If the foot has high supination resistance, it means a lot of force is required to achieve this motion, potentially leading to inefficient gait mechanics and increased risk for overuse injuries.

Several factors influence supination resistance, including the alignment of the subtalar joint, midtarsal joint mobility, body weight, and even soft tissue flexibility. For instance, individuals with a medially deviated subtalar joint axis often have higher supination resistance because ground reaction forces act more medially, increasing the lever arm for pronatory forces. Conversely, someone with a more laterally placed subtalar axis may have lower resistance. Clinically, high supination resistance is often associated with persistent pronation, flat feet (pes planus), and conditions like posterior tibial tendon dysfunction, while low supination resistance may correlate with rigid high-arched feet (pes cavus) that don’t adapt well to ground surfaces.

Understanding supination resistance is important for treatment planning, especially when prescribing foot orthotics. Patients with high supination resistance may need orthotics that provide more aggressive arch support or medial posting to control pronation. On the other hand, for those with low resistance, excessive correction can actually destabilize the foot. Some clinicians use devices like a supination resistance meter, but often manual testing provides sufficient clinical information. Ultimately, evaluating supination resistance helps personalize interventions, optimize gait, and reduce injury risk.

Most Useful Resources:
https://podiapaedia.org/wiki/biomechanics/clinical-biomechanics/concepts/supination-resistance/ (PodiaPaedia)
https://podiatryarena.com/index.php?articles/supination-resistance.1/ (Podiatry Arena)
https://podiatryarena.com/index.php?tags/supination-resistance/ (Podiatry Arena)
http://www.runresearchjunkie.com/the-concept-of-supination-resistance/ (Running Research Junkie)
http://www.podiatryfaq.com/supination-resistance/ (Podiatry FAQ)
http://www.ipodiatry.org/the-concept-of-supination-resistance/13688 (iPodiatry)

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Foot Posture Index

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Foot Posture Index is a composite measure of the posture of the foot based on 6 different observations of the alignment or posture of different segments of the foot.

The Foot Posture Index (FPI) is a widely used clinical tool for quantifying standing foot posture, helping to classify feet as pronated, neutral, or supinated. The most common version is the FPI-6, which involves observing and scoring six specific criteria. This assessment is quick, simple, and reliable, making it valuable for clinicians and researchers alike.

Here’s how to calculate the FPI-6:

1. Preparation and Patient Positioning
The patient should stand barefoot in a relaxed, neutral stance with both feet supporting their weight. Their arms should be naturally at their sides, and they should look straight ahead. It can be helpful to have them march in place for a few steps before settling into their stance. The assessment usually takes about two minutes, and the assessor needs to be able to move around the patient freely.

2. The Six Criteria and Scoring
Each of the six criteria is scored on a 5-point scale, ranging from -2 to +2. A score of 0 indicates a neutral position for that specific criterion. Positive values (+1, +2) are given for pronated features, with higher scores indicating more pronation. Negative values (-1, -2) are given for supinated features, with more negative scores indicating more supination. If an observation cannot be made (e.g., due to swelling), it should be skipped and noted.

The six criteria are:

  • Talar Head Palpation (Transverse Plane): This involves palpating the talar head. The score depends on whether the talar head is more palpable on the lateral (outer) or medial (inner) side of the foot.
  • Curves Above and Below the Lateral Malleolus (Frontal/Transverse Plane): Observe the curvature around the ankle bone (lateral malleolus) from behind. The score is based on whether the curve below the malleolus is straight, convex, or more or less concave compared to the curve above it.
  • Calcaneal Frontal Plane Position (Frontal Plane): Observe the heel bone (calcaneus) from behind. The score reflects whether the heel is inverted (varus), everted (valgus), or vertical, often estimated in degrees.
  • Prominence in the Region of the Talonavicular Joint (Transverse Plane): View the inside of the foot at an angle. The score depends on whether this area is concave, flat, or bulging.
  • Congruence of the Medial Longitudinal Arch (Sagittal Plane): Observe the inner arch of the foot from the inside. The score ranges from a high, acutely angled arch to a very low, flattened arch that might be making ground contact.
  • Abduction/Adduction of the Forefoot on the Rearfoot (Transverse Plane): View the foot from behind. The score is based on how many medial (inner) or lateral (outer) toes are visible, indicating whether the forefoot is abducted (splayed out) or adducted (turned in) relative to the rearfoot.

3. Total Score and Classification
After scoring each of the six items, sum the individual scores to get a total FPI-6 score. The total score can range from -12 (severely supinated) to +12 (severely pronated). The foot posture is then classified based on this total score:

  • Severely Supinated: ≤ -5
  • Mildly Supinated: -1 to -4
  • Neutral Posture: 0 to +5
  • Mildly Pronated: +6 to +9
  • Severely Pronated: ≥ +10

It’s important to note that a slightly pronated foot posture (mean raw score of +4) is considered the normal position at rest in a healthy adult population. The FPI is a practical tool that aids in deciding appropriate interventions, such as strengthening exercises, stretching, manual therapy, gait training, or selecting suitable orthotics.

Most Useful Resources:
Foot Posture Index (Podiatry TV)
The Foot Posture Index (Podiatry Update)
Foot Posture Index (Clinical Boot Camp)
Foot Posture Index (PodiaPaedia)
Foot Posture Index (Podiatry Arena)

Cluffy Wedge

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The Cluffy wedge is a pad that is places under the great toe to hold it in a slightly dorsiflexed position. It is designed to treat functional hallux limitus and problems with the windlass mechanism.

The Cluffy Wedge is a trademarked pad designed to sit under the hallux (your big toe), aiming to hold it in a gently dorsiflexed position—that is, lifted upward just enough to get things moving right. Originally developed by Dr. James Clough, DPM, this wedge was first trademarked in 2003 under Cluffy LLC in Polson, Montana, and has also been marketed under the name P4 Wedge.

Functionally, the Cluffy Wedge is all about managing a condition called functional hallux limitus—where your big toe has a normal range of motion when off the ground but gets stuck when you’re weight-bearing. By dorsiflexing the hallux, the wedge preloads the toe so the windlass mechanism (which tightens the plantar fascia during walking) kicks in earlier and more naturally . The theory is sound: first metatarsal loading improves, less strain is placed on the other metatarsals, and the foot’s biomechanics get realigned—at least hypothetically.

On the practical side, you can use the Cluffy Wedge on its own inside shoes, under insoles, or as an extension in custom orthotics. While some podiatric labs initially offered it, most now craft their own versions to achieve the same effect—often by adding padding under the hallux in custom orthotic designs. However, it’s important to note that peer-reviewed clinical trials are lacking, so much of what we have are anecdotal reports, small-scale studies, or theses—not yet full clinical validation.

In short, the Cluffy Wedge stands out as a simple yet biomechanically savvy tool for specific foot dysfunctions, especially functional hallux limitus. While its theoretical benefits—like balancing forefoot pressure and reactivating the windlass mechanism—are appealing, we remain a bit short on robust clinical research. Still, for patients and practitioners looking for non-invasive ways to support hallux mechanics, it’s worth considering, especially if integrated thoughtfully into custom orthotic planning.

Most Useful Resources:
Cluffy Wedge (Foot Health Forum)
Cluffy Wedge (Podiatry Arena)
Cluffy Wedge (Clinical Biomechanics Bootcamp)
Cluffy Wedge (PodiaPaedia)
The Cluffy Wedge (Podiatry Update)
Cluffy Wedge (Podiatry Experts)

Congenital Vertical Talus

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Congenital Vertical Talus is a severe cause of flat foot (or overpronation) in kids. The talus is almost vertically, pointing plantarly so that the navicular bone is articulating with the top of the head of the talus. Surgery is usually the only satisfactory treatment.

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Congenital Vertical Talus (CVT), sometimes referred to as “rocker-bottom foot,” is a rare but serious foot deformity present at birth. It is characterized by a rigid flatfoot where the talus bone is abnormally positioned in a vertical orientation instead of its normal horizontal alignment. This abnormality causes the midfoot and forefoot to dislocate dorsally (upward) over the talus, resulting in the distinctive convex shape of the sole. Unlike more common flexible flatfoot in children, CVT is a rigid deformity that does not improve with growth, making early recognition essential for effective treatment.

Causes and Associations
The exact cause of congenital vertical talus is not fully understood, but it is generally thought to arise from disruptions in fetal musculoskeletal development. CVT can occur in isolation or be associated with neuromuscular and genetic conditions such as arthrogryposis, spina bifida, or other syndromic disorders. In some cases, it appears as an isolated idiopathic deformity without underlying systemic disease. The condition affects both feet in about half of the cases and is slightly more common in males than females. Its rarity often contributes to delayed diagnosis unless clinicians are specifically familiar with the condition.

Clinical Presentation and Diagnosis
At birth, CVT is typically recognized by the distinct “rocker-bottom” appearance of the foot, with a rigid upward bend in the midfoot and a prominent heel. Unlike flexible flatfoot, manipulation does not restore the arch. Radiographic imaging confirms the diagnosis, showing the talus bone in a vertical position and misalignment of other midfoot structures. X-rays taken in both plantarflexion and dorsiflexion are especially helpful in distinguishing CVT from other similar deformities, such as calcaneovalgus foot or oblique talus. Early diagnosis is critical, as untreated CVT can lead to severe disability, impaired walking, and chronic pain.

Treatment and Prognosis
Treatment typically involves early, structured intervention. Historically, surgery was the mainstay, but current best practices favor staged correction through serial casting (often similar to the Ponseti method used for clubfoot), followed by limited surgical procedures such as tendon lengthening or soft-tissue releases to correct residual deformities. In some cases, subtalar or talonavicular joint stabilization may be necessary. With timely intervention, most children achieve good functional outcomes, including near-normal walking and foot appearance. However, delayed or inadequate treatment can result in permanent disability, making early recognition and multidisciplinary care essential for long-term mobility and quality of life.

Most Useful Resources:
Congenital Vertical Talus (Foot Health Forum)
Congenital Vertical Talus (Podiatry Arena)
Congenital Vertical Talus (PodiaPaedia)
C is for Congenital Vertical Talus (Podiatry ABC)

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Overpronation

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‘Overpronation’ is generally accepted as being the foot rolling inwards at the ankle or rearfoot joints. There is a lot of controversy about the use of the term; just how much of a risk factor for injury it is; if it should be treated or not; and what the best treatment for it should be.

overpronation

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Overpronation in runners refers to an excessive inward rolling of the foot after it strikes the ground during running. While some degree of pronation is natural and helps absorb shock, overpronation places extra stress on the foot and leg. When the foot rolls too far inward, it disrupts proper alignment and alters how forces are distributed across the lower body. This can affect not only the feet but also the ankles, knees, hips, and even the lower back, making it a common biomechanical issue among runners.

One of the main causes of overpronation is structural or biomechanical imbalances. Flat feet, low arches, and ligament laxity often predispose runners to roll their feet inward. Other contributing factors include weak stabilizing muscles in the hips and legs, improper running technique, or wearing shoes without sufficient support. Over time, these factors can combine to exaggerate the inward collapse of the foot, leading to poor shock absorption and inefficient running mechanics.

The symptoms and risks of overpronation are varied. Runners often experience pain in the arch or heel, shin splints, plantar fasciitis, Achilles tendonitis, and knee discomfort due to the misalignment of the leg. Overpronation may also contribute to overuse injuries, since the body compensates for poor foot mechanics with increased stress on surrounding joints and muscles. Recognizing these symptoms early can help runners avoid more serious chronic injuries that could interrupt training.

Management and prevention strategies typically involve strengthening exercises, supportive footwear, and sometimes orthotics. Strengthening the intrinsic foot muscles, calves, and hip stabilizers can improve foot control and alignment. Choosing stability or motion-control running shoes with proper arch support can reduce excessive pronation. For runners with more severe cases, custom orthotics may be prescribed to correct biomechanics. Additionally, focusing on proper running form and gradually increasing training load can reduce the likelihood of injury from overpronation. This balanced approach allows runners to maintain performance while protecting long-term joint health.

Most Useful Resources:
Overpronation (Foot Health Forum)
Overpronation in Runners (Podiatry Update)
Overpronation (Podiatry Online TV)
How do you treat overpronation? (Podiatry Experts)
My Advice if you Overpronate (Running Injury Advice)
Overpronation (Dr the Foot Without the Dr)
‘Overpronation’ (Podiatry CPD)
Pronation Mythology (Its a foot, Captain)
The nonsensical understanding of ‘overpronation’ (Run Research Junkie)
Is Overpronation a Problem? (Clinical Boot Camp)
“Biomechanics Corner”: Overpronation (Podiatry Arena)
Overpronation (Foot Info)
Overpronation (Podiatry Daily)

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Accessory Navicular

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The accessory navicular is an extra bone on the medial side of the navicular that can cause pain due to pressure on the lump from footwear (especially things like ice skates) and also be a factor in flat or overpronated feet due to changes in the pull of the tendon from the muscle that is the main supporter of the arch of the foot.

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The accessory navicular (AN) is a common anatomical variation of the foot that can cause discomfort and pain in some individuals. It is an extra bone or piece of cartilage located on the inner side of the foot, near the arch.
What is an Accessory Navicular?
The accessory navicular is a congenital condition, meaning it is present at birth. It is estimated that around 10-15% of the general population has an AN, although not all individuals with this condition will experience symptoms. The AN can be classified into three types:
  • Type 1: A small, rounded ossicle (bone) within the posterior tibial tendon.
  • Type 2: A larger, triangular-shaped bone connected to the navicular bone by a synchondrosis (cartilaginous joint).
  • Type 3: A bony prominence that is fused to the navicular bone.
Symptoms of Accessory Navicular
While many individuals with an accessory navicular do not experience symptoms, others may develop pain and discomfort due to various factors, such as:
  • Overuse or repetitive strain: Activities that involve repetitive stress on the foot, such as running or dancing, can cause irritation and inflammation.
  • Poor foot mechanics: Abnormal foot pronation or supination can put additional stress on the AN, leading to pain and discomfort.
  • Trauma: A direct blow to the foot or a sudden injury can cause pain and inflammation in the AN.
Common symptoms of accessory navicular include:
  • Pain or tenderness: On the inner side of the foot, near the arch.
  • Swelling or redness: Around the AN.
  • Limited mobility: Stiffness or limited range of motion in the foot or ankle.
  • Difficulty walking: Pain or discomfort while walking or engaging in activities.
Diagnosis and Treatment
Diagnosis of accessory navicular typically involves a combination of:
  • Physical examination: A healthcare professional will assess the foot and ankle for pain, tenderness, and range of motion.
  • Imaging studies: X-rays, CT scans, or MRI scans may be used to confirm the presence of an AN.
Treatment for accessory navicular depends on the severity of symptoms and may include:
  • Conservative management: Rest, ice, compression, and elevation (RICE) can help alleviate pain and inflammation.
  • Orthotics and shoe modifications: Custom orthotics or shoe inserts can help redistribute pressure and reduce stress on the AN.
  • Physical therapy: Stretching and strengthening exercises can help improve foot mechanics and reduce pain.
  • Surgery: In some cases, surgical removal of the AN or repair of the posterior tibial tendon may be necessary.
Prevention and Management
While it is not possible to prevent an accessory navicular, there are steps that can be taken to reduce the risk of symptoms:
  • Wear supportive shoes: Choose shoes with good arch support and cushioning.
  • Use orthotics: Custom orthotics can help redistribute pressure and reduce stress on the AN.
  • Stretch and strengthen: Regular stretching and strengthening exercises can help improve foot mechanics and reduce pain.

Most Useful Resources:
Accessory Navicular (PodiaPaedia)
Surgery for accessory navicular (Podiatry Arena)
Accessory navicular (Podiatry Arena)
Classification of the Accessory Navicular (Podiatry Ninja)
Accessory Navicular (Foot Health Forum)

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