flat feet | Podiatry Help

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)

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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