The Foot Posture Index has is is becoming the most valid measure of determining the posture of the foot.
The Foot Posture Index (FPI) is a clinical tool used to assess the posture and alignment of the foot. It is a measurement system that helps healthcare professionals evaluate various aspects of foot structure and categorize them into different foot posture types. The FPI is widely used in podiatry and foot health fields.
Purpose: The primary purpose of the Foot Posture Index is to provide a standardized and objective method of assessing foot posture. It helps in determining whether a person has a pronated (flat) foot, supinated (high-arched) foot, or a foot with a neutral posture.
Components: The FPI assesses six different components of foot posture: talar head palpation, curves above and below the lateral malleoli (bony bumps on the outer side of the ankle), calcaneal (heel) position, prominence in the region of the talonavicular joint, congruence of the medial longitudinal arch, and abduction/adduction of the forefoot.
Scoring: Each component of the FPI is given a numerical score ranging from -2 to +2, representing different degrees of deviation from a neutral foot posture. A score of 0 indicates a neutral foot posture, while negative scores indicate a pronated foot and positive scores indicate a supinated foot.
Total Score and Classification: The individual component scores are summed to calculate a total score, which can range from -12 to +12. The total score is then classified into different foot posture categories, such as highly pronated, pronated, neutral, supinated, or highly supinated.
Reliability and Validity: The FPI has been subjected to rigorous testing and has demonstrated good reliability and validity. It has been shown to have good inter- and intra-rater reliability, meaning that different healthcare professionals can achieve consistent results when using the FPI. The FPI has also shown correlations with other measures of foot structure and function.
Clinical Application: The FPI is commonly used in clinical practice to assist with foot posture assessment, treatment planning, and monitoring changes in foot posture over time. It can help healthcare professionals identify foot posture abnormalities, guide interventions such as orthotic prescription or exercise programs, and track the effectiveness of treatment.
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Foot Posture Index FAQ’s:
What is the Foot Posture Index?
The Foot Posture Index (usually the six-item version, FPI-6) is a quick clinical tool used by podiatrists, physiotherapists, and other clinicians to quantify standing foot posture. It classifies a foot as more pronated, neutral, or more supinated based on six visual and palpatory observations. Developed by Anthony Redmond and colleagues, it provides a single score reflecting multi-planar, multi-segment foot alignment in relaxed double-limb stance.
What are the six items assessed in the FPI-6?
Each item is scored from –2 to +2:
- Talar head palpation (how prominent the talar head feels medially vs laterally)
- Curves above and below the lateral malleolus (supra- and infra-malleolar curvature)
- Calcaneal frontal-plane position (inversion/eversion of the heel viewed from behind)
- Prominence/bulging in the region of the talonavicular joint
- Congruence and height of the medial longitudinal arch
- Abduction/adduction of the forefoot on the rearfoot (how many toes are visible from behind)
Positive scores indicate pronated features; negative scores indicate supinated features; zero is neutral for that criterion.
How is the FPI scored and what does the total score mean?
Scores for the six items are simply added. The total ranges from –12 (highly supinated) to +12 (highly pronated).
Common classification ranges (slight variations exist across sources):
- Highly supinated: ≤ –5 (or –12 to –5)
- Supinated: –4 to –1
- Normal / neutral: 0 to +5 (some sources use +1 to +7)
- Pronated: +6 to +9
- Highly pronated: ≥ +10
A score of zero is not necessarily the population average.
What is a “normal” FPI score?
In healthy adults the mean FPI-6 score is approximately +4 (slightly pronated). The normal range is often considered roughly 0 to +5 or +1 to +7 (within about one standard deviation of the adult mean). Children and older adults tend to have slightly higher (more pronated) average scores. Gender and BMI have little influence.
How do you perform the assessment?
The patient stands in a relaxed, comfortable double-limb stance (feet roughly shoulder-width apart, looking straight ahead, arms by sides). They should not try to “correct” their posture or swivel to watch the examiner. Each foot is scored independently. The assessment typically takes 1–3 minutes once the clinician is experienced. When in doubt about a score, the more conservative value is chosen.
Is the Foot Posture Index reliable and valid?
Intra-rater reliability is generally good to excellent. Inter-rater reliability is moderate to good (better with experienced examiners and clear protocols). It shows acceptable concurrent validity against other clinical and some kinematic measures of foot posture and correlates with certain radiographic parameters. It is widely regarded as one of the more practical and multi-planar clinical tools available, though it is not a perfect substitute for instrumented gait analysis or imaging.
Why does foot posture matter clinically?
Foot posture influences lower-limb alignment and loading. Highly pronated or highly supinated postures have been associated with increased risk or presence of various musculoskeletal problems (e.g., plantar fasciitis, patellofemoral pain, medial tibial stress syndrome, certain ankle injuries, and sometimes low-back pain). The FPI helps classify foot type, guide orthotic prescription, monitor change, and stratify patients in research. It is a static measure and should be interpreted alongside history, dynamic assessment, and symptoms.
Does the FPI measure dynamic function during walking or running?
No. The FPI assesses static standing posture only. While static posture shows moderate associations with some dynamic measures, it does not fully predict kinematics or loading during gait. Clinicians usually combine it with functional tests, gait observation, or pressure analysis when needed.
Who developed the FPI and is there an official manual?
The FPI was developed by Professor Anthony C. Redmond and colleagues (University of Sydney / University of Leeds). A free user guide and manual for the six-item version (FPI-6) is available and is the recommended version; earlier eight-item versions are no longer advised.
Can I use the FPI on children or older adults?
Yes. Normative values exist for different age groups. Children and older adults tend to score slightly higher (more pronated) on average than young/middle-aged adults. Reliability remains acceptable in these populations when the tool is applied carefully.
Are there limitations I should know about?
- It is a static, observational tool and does not capture dynamic behaviour.
- Inter-rater reliability can vary with examiner experience.
- Extreme soft-tissue changes, oedema, or deformity can make some criteria harder to score.
- Cut-off values for “normal” vs “abnormal” should be used as guides rather than rigid diagnostic thresholds.
- It should not be the sole basis for treatment decisions.