The Foot and Ankle Outcome Score, or FAOS, is a 42-item patient-reported outcome measure used to assess foot- and ankle-related pain, symptoms, daily function, sport and recreation function, and quality of life. It helps professionals track how a client perceives their foot or ankle problem over time, but it does not diagnose a condition, confirm pathology or determine return-to-sport readiness on its own.

Introduction

Foot and ankle problems can affect walking, running, stairs, jumping, balance, footwear tolerance, work demands, sport participation and confidence with daily movement.

The Foot and Ankle Outcome Score, commonly called the FAOS, is a patient-reported outcome measure designed to capture the client’s own view of their foot or ankle symptoms and function.

It is commonly used for:

• ankle sprain
• chronic ankle instability
• ankle fracture recovery
• Achilles-related presentations
• plantar heel pain
• foot and ankle osteoarthritis
• post-operative foot or ankle recovery
• sport and recreation limitations
• long-term progress tracking

The FAOS includes five subscales: Pain, Symptoms, Activities of Daily Living, Sport and Recreation, and Foot/Ankle-Related Quality of Life. Each subscale is transformed to a 0–100 score, where 100 represents no problems and 0 represents extreme problems.  

This article uses the Measurz Evidence-First Outcome Measure Article Optimiser structure, including scoring, population-specific interpretation, meaningful change, reliability, validity and Measurz recording guidance.

Quick Summary

• Outcome measure: Foot and Ankle Outcome Score
• Abbreviation: FAOS
• Body region: Foot and ankle
• Type: Patient-reported outcome measure
• Number of items: 42
• Subscales: Pain, Symptoms, Activities of Daily Living, Sport/Recreation, Quality of Life
• Score range: 0–100 for each subscale
• Higher score means: Better perceived foot and ankle status
• Lower score means: More pain, symptoms, limitation or quality-of-life impact
• Best used for: Baseline assessment, reassessment, progress tracking and outcome reporting
• Key limitation: FAOS does not diagnose a condition or clear someone for sport on its own

What Is the Foot and Ankle Outcome Score?

The FAOS is a foot- and ankle-specific questionnaire designed to measure the client’s perceived symptoms, function and quality of life.

It includes five subscales:

• Pain
• Other Symptoms
• Activities of Daily Living
• Sport and Recreation Function
• Foot- and Ankle-Related Quality of Life

The FAOS was developed from the structure of the Knee injury and Osteoarthritis Outcome Score and adapted for foot and ankle conditions. The original validation work studied people undergoing ankle ligament reconstruction, and later studies have examined its use across other foot and ankle populations.  

Why It Is Used

The FAOS is useful because physical tests do not always explain how a client experiences their foot or ankle problem.

A client may show improving range of motion, strength or balance but still report:

• difficulty walking longer distances
• pain with stairs
• poor confidence on uneven ground
• difficulty returning to running
• reduced sport participation
• swelling or stiffness after activity
• frustration with recurring symptoms
• reduced quality of life

The FAOS can help professionals:

• establish a baseline
• identify which domains are most affected
• monitor change over time
• support client education
• guide goal-setting conversations
• compare symptoms and function across reassessments
• combine client-reported outcomes with objective testing
• improve reporting quality in Measurz

The FAOS should support assessment reasoning and progress tracking. It should not be used as a stand-alone diagnostic, treatment or clearance tool.

What It Measures

Pain

The Pain subscale captures pain frequency and pain during common activities.

It may provide insight into pain during:

• walking
• standing
• stairs
• loading tasks
• rest
• night-time symptoms

Symptoms

The Symptoms subscale captures other foot and ankle symptoms, such as:

• swelling
• stiffness
• restricted movement
• mechanical symptoms
• general symptom severity

Activities of Daily Living

The ADL subscale captures day-to-day function.

This may include:

• walking on flat ground
• stairs
• standing
• household tasks
• getting in and out of positions
• general daily mobility

Sport and Recreation

The Sport/Recreation subscale captures higher-demand activities.

This may include:

• running
• jumping
• twisting
• pivoting
• cutting
• recreational activity
• sport participation

Foot- and Ankle-Related Quality of Life

The Quality of Life subscale captures broader personal impact.

This may include:

• confidence
• frustration
• lifestyle impact
• awareness of the foot or ankle problem
• participation restriction
• perceived long-term impact

Who It Is Useful For

The FAOS may be useful for:

• exercise professionals
• rehabilitation practitioners
• strength and conditioning coaches
• allied health support teams
• performance professionals
• movement assessment professionals
• students learning outcome measures
• professionals using Measurz or MAT for structured progress tracking

It may be relevant for clients with:

• acute ankle injury
• chronic ankle instability
• ankle fracture
• Achilles tendon symptoms
• plantar heel pain
• foot pain
• ankle osteoarthritis
• post-operative foot or ankle recovery
• sport-related foot and ankle limitations
• persistent swelling, stiffness or pain

When to Use This Outcome Measure

Use the FAOS when you want to understand how a foot or ankle problem affects the client’s symptoms, function and quality of life.

It may be useful at:

• initial assessment
• onboarding
• reassessment
• post-injury monitoring
• post-operative milestones
• return-to-running planning
• return-to-sport planning
• discharge or progress review

The FAOS is most useful when repeated over time using the same version and scoring method.

When Not to Use or When to Be Cautious

Use caution when:

• the client cannot complete the questionnaire independently
• literacy, language or cognitive factors affect responses
• the wrong language version is being used
• the client has multiple body regions contributing to limitation
• the client has not attempted the activities being scored
• many items are missing
• the score is being used as a pass/fail decision
• the result is interpreted without physical assessment context

The FAOS should not be used to:

• diagnose a condition
• confirm injury
• determine tissue healing
• identify the exact cause of symptoms
• clear someone for sport
• replace professional judgement
• replace medical assessment when needed

Equipment or Resources Required

• FAOS questionnaire
• Official scoring guidance or validated calculator
• Measurz recording workflow
• Client-reported symptom and function notes
• Baseline and retest dates
• Optional related physical test results, such as:
  • ankle range of motion
  • weight-bearing lunge test
  • calf strength testing
  • single-leg balance
  • hop testing
  • gait or running assessment
  • swelling or girth measures

Administration Protocol / Practice

Setup

Explain the purpose of the questionnaire before the client completes it.

Example wording:

“This questionnaire helps us understand how your foot or ankle is affecting your pain, symptoms, daily function, sport and quality of life. It does not diagnose the problem on its own, but it helps us monitor change over time.”

Format

The FAOS can be completed:

• on paper
• digitally
• independently
• with assistance
• before a session
• during reassessment
• as part of a Measurz workflow

Client Instructions

Ask the client to:

• answer based on their current foot or ankle problem
• choose the response that best matches their experience
• answer every item where possible
• avoid overthinking each question
• ask for clarification if they do not understand the wording
• complete the same version at each retest

Completion Method

Record whether the FAOS was completed:

• independently
• digitally
• on paper
• verbally
• with assistance

This matters because assistance, wording clarification or completion format may influence responses.

Assistance Rules

If help is required:

• explain instructions without leading the answer
• avoid telling the client which option to choose
• record that assistance was provided
• use the same assistance approach at retest where possible

Missing Item Handling

Do not guess missing responses.

Use the official scoring guidance for the version being used. If too many items are missing for a subscale, record that subscale as incomplete rather than creating an unreliable score.

Scoring Process

Each item is scored from 0 to 4.

Each subscale is transformed to a 0–100 score.

General scoring direction:

• 100: no foot or ankle problems
• 0: extreme foot or ankle problems

The five subscales should be interpreted separately rather than combined into one unsupported total score.

Retesting Considerations

Retest at meaningful time points, such as:

• baseline
• after a training block
• after a rehabilitation phase
• pre-return to running
• pre-return to sport
• after a flare-up
• after post-operative milestones
• discharge or progress review

For consistency, record:

• date
• current activity level
• recent flare-ups
• recent training load
• whether the client has returned to the activities being scored
• any major changes in work, sport or footwear demands

Safety Notes

The FAOS is a self-report questionnaire, so it does not create physical testing risk.

However, a major worsening in score may support further assessment if the client reports:

• severe deterioration
• major quality-of-life impact
• worsening function
• severe pain or swelling
• unexpected decline
• new symptoms

Scoring and Interpretation

The FAOS has five separate subscale scores.

Each subscale ranges from 0 to 100.

Higher scores indicate better perceived foot and ankle status.

Lower scores indicate more reported problems.

Subscales

• Pain: 0–100
• Symptoms: 0–100
• Activities of Daily Living: 0–100
• Sport/Recreation: 0–100
• Quality of Life: 0–100

What a High Score May Suggest

A higher score may suggest:

• fewer symptoms
• less pain
• better daily function
• better sport or recreation function
• better perceived quality of life
• improved confidence with the foot or ankle

What a Low Score May Suggest

A lower score may suggest:

• more pain
• more symptoms
• reduced daily function
• reduced sport or recreation capacity
• reduced confidence
• greater quality-of-life impact

What the Score Does Not Prove

A FAOS score does not prove:

• the diagnosis
• the tissue source of symptoms
• the severity of structural injury
• readiness to return to sport
• whether imaging is required
• whether a specific intervention caused the change

How to Explain the Result Safely

Example wording:

“Your FAOS results show that your daily function has improved, but sport and recreation are still more limited. This does not tell us exactly what structure is causing symptoms, but it helps us understand how your foot or ankle is affecting the activities that matter to you.”

What the Score May Mean in Different Client Populations

General Fitness Clients

For general fitness clients, FAOS can help show how foot or ankle symptoms affect:

• walking
• stairs
• gym training
• daily activity
• recreational exercise

Interpretation cautions:

• scores may change with recent activity
• pain expectations may influence responses
• sport items may be less relevant if the client does not participate in sport

Sport and Performance Clients

For athletes, the Sport/Recreation and Quality of Life subscales are often especially important.

A client may score well on daily activities but still report limitations with:

• running
• jumping
• cutting
• landing
• uneven ground
• confidence in competition

Interpretation should include sport-specific testing. A high FAOS score should not be treated as return-to-sport clearance on its own.

Older Adults

For older adults, FAOS may help identify how foot and ankle symptoms influence:

• walking tolerance
• stairs
• balance confidence
• participation
• independence

Interpretation cautions:

• other health conditions may affect scores
• general strength and balance may influence responses
• broad reference values should be used cautiously

Youth Clients

FAOS may be less appropriate for some younger clients depending on comprehension and version suitability.

Consider:

• age
• literacy
• parent or guardian assistance
• sport exposure
• whether the questionnaire wording fits the client

Clients With Persistent Symptoms

For persistent symptoms, FAOS can help monitor long-term impact beyond pain alone.

Scores may be influenced by:

• confidence
• fear of recurrence
• activity avoidance
• frustration
• flare-up patterns
• participation restrictions

Clients Returning After Injury

FAOS can help show whether perceived function is improving during return-to-activity planning.

However:

• high FAOS scores should not be used as clearance on their own
• sport-specific capacity should still be tested
• strength, ROM, balance, hop and workload measures should be considered

Higher Body Mass Clients

Body mass may influence foot and ankle symptoms, function and reference score interpretation. The 2023 Danish FAOS reference study included supplemental questions on previous foot and ankle problems and body mass index, supporting the need to interpret broad reference values in context.  

Post-Surgical Clients

For post-operative clients, FAOS can help track perceived recovery over time.

Interpretation should consider:

• surgical procedure
• healing stage
• expected restrictions
• activity exposure
• swelling and pain patterns
• medical or surgical guidance where relevant

Meaningful Change, MCID, MDC and Responsiveness

Meaningful change values help interpret whether a score change is likely to matter.

Key terms:

• MCID / MIC: the smallest change that may be meaningful to clients or professionals, depending on the method used
• MDC: the amount of change likely needed to exceed measurement error
• SEM: the estimated measurement error around a score
• Responsiveness: the ability of the measure to detect change over time

FAOS Minimal Important Change

A 2021/2022 study examined minimal important change values for FAOS in people who underwent operative treatment for foot and ankle conditions. The authors noted that FAOS is widely used, but more evidence on longitudinal validity was needed; the study used predictive modelling to estimate minimal important change values.  

A separate ankle fracture recovery study examined FAOS validity, reliability, responsiveness and minimal clinically important difference during early recovery after ankle fracture. Those findings are useful for ankle fracture contexts, but they should not be automatically applied to all foot and ankle conditions.  

Practical Interpretation

When interpreting change:

• compare each subscale to baseline
• check whether the change exceeds available MIC, MCID, MDC or SEM for the relevant population
• look for consistent improvement across relevant subscales
• compare the score change with client goals
• check whether activity exposure has increased
• consider pain, swelling, strength, ROM and balance findings

When Values Are Uncertain

Reported meaningful change values may vary by:

• condition
• language version
• surgical versus non-surgical population
• follow-up timeframe
• anchor method
• scoring method
• baseline severity

Use the value that best matches the client group and testing context. Where no matching value exists, rely more heavily on baseline comparison, repeated measurement, client-reported change, physical assessment and professional judgement.

Normative Data, Reference Values or Comparative Data

Published FAOS reference values are available.

A 2023 national representative sample study established FAOS reference values using Danish adult population data. The sample was drawn from 9,996 adult citizens, with 2,759 completed FAOS responses. The study was designed because FAOS is widely used but reference values were missing to help interpretation.  

These reference values provide useful context, but interpretation should consider whether the reference population matches the client’s:

• age
• sex
• country
• health status
• injury status
• surgical history
• BMI
• activity level
• sport or work demands

Practical guidance:

• Scores closer to 100 generally suggest fewer reported problems.
• Lower scores suggest greater pain, symptoms, functional limitation or quality-of-life impact.
• Sport/Recreation and Quality of Life may remain limited even after daily function improves.
• Population reference values provide context, not strict pass/fail thresholds.
• The client’s own baseline is often the most useful comparison.

A 10-point FAOS difference across subscales was predefined as clinically relevant in the 2023 reference value study, but this should be treated as a study-specific interpretation threshold rather than a universal pass/fail rule.  

Reliability and Validity

The FAOS has been studied across several foot and ankle populations.

Evidence supports its use as a foot- and ankle-specific patient-reported outcome measure, although measurement properties can vary depending on:

• condition
• language version
• population
• scoring method
• follow-up timeframe
• baseline severity

The original FAOS validation work supported its use after ankle ligament reconstruction.  

A 2018 systematic review examined the measurement properties of commonly used foot- and ankle-specific questionnaires, including FAOS, FFI and FAAM. The review found that FAOS and FAAM were promising, but also noted that limitations should be considered when interpreting results.  

More recent validation work has examined FAOS in populations such as chronic ankle instability and ankle osteochondral lesions, supporting its broader use while still requiring population-specific interpretation.  

Reliability and validity are stronger when:

• the correct version is used
• the same scoring method is repeated
• all relevant items are completed
• subscales are interpreted separately
• retesting occurs at meaningful time points
• results are interpreted alongside physical and functional assessment

Interpret cautiously when:

• many items are missing
• the client has not attempted sport or work tasks yet
• only one subscale changes slightly
• the change is smaller than known measurement error or meaningful change
• symptoms are strongly influenced by a recent flare-up
• the score is being used without objective assessment context

Common Errors and Limitations

Common errors include:

• treating FAOS as a diagnosis
• using one score as a clearance decision
• combining subscales into an unsupported total score
• ignoring missing items
• using inconsistent scoring methods
• not recording the version used
• not recording the completion date
• comparing scores without considering activity exposure
• over-interpreting small changes
• using reference values as strict pass/fail cut-offs

Limitations include:

• self-report can be influenced by mood, expectations and recent activity
• sport items may be less meaningful if the client has not returned to sport
• scores do not identify the exact physical cause of symptoms
• MCID, MDC and SEM values may vary across populations
• reference values may not match the client’s age, sport, country or condition
• FAOS should be paired with physical tests and client goals

Practical Applications

The FAOS may help professionals:

• document baseline foot and ankle status
• identify whether pain, symptoms, sport or quality of life are most affected
• track change over time
• monitor post-injury or post-surgical recovery
• support goal setting
• improve client education
• communicate progress with a broader team
• strengthen Measurz reports

For athletes, FAOS can help identify whether sport and recreation are still limited after daily function improves.

For general population clients, it may help track walking, stairs, swelling, pain and participation.

For persistent symptoms, it can show whether the condition is affecting confidence, lifestyle and activity choices.

For Measurz users, FAOS is most useful when combined with objective measures such as:

• ankle dorsiflexion ROM
• calf strength
• single-leg balance
• hop testing
• gait or running assessment
• swelling measures
• pain with key movements

How to Record This in Measurz

Record:

• outcome measure name: Foot and Ankle Outcome Score / FAOS
• version used
• date completed
• completion method: paper, digital, interview or assisted
• language/version used
• condition or presentation being tracked
• side involved: left, right or bilateral
• Pain subscale score
• Symptoms subscale score
• ADL subscale score
• Sport/Recreation subscale score
• Quality of Life subscale score
• score range: 0–100
• direction of scoring: higher score indicates better status
• missing items, if any
• assistance provided, if any
• current pain score, if relevant
• current symptoms
• current activity or sport exposure
• key functional limitations
• confidence or participation goals
• baseline comparison
• MCID/MDC/MIC comparison where supported
• related physical assessment findings
• interpretation notes
• retest date
• referral or further assessment notes where appropriate

Record whether the main limitation appears to be:

• pain dominant
• symptom or swelling dominant
• daily function limitation
• sport/recreation limitation
• quality-of-life limitation
• mixed presentation
• unclear due to incomplete responses

This improves:

• repeatability
• communication
• client education
• assessment reasoning
• monitoring over time
• team consistency
• reporting quality

Related Outcome Measures / Internal Links

Use the related outcome-measure articles below to build internal linking between body regions, function scales, pain beliefs and return-to-activity monitoring.

• Foot & Ankle Disability Index / FADI
• Lower Extremity Functional Scale / LEFS
• Knee Injury and Osteoarthritis Outcome Score / KOOS
• Lysholm Knee Scoring Scale
• Copenhagen Hip and Groin Outcome Score / HAGOS
• Hip Disability and Osteoarthritis Outcome Score / HOOS
• Oswestry Disability Questionnaire
• Quebec Back Pain Disability Scale
• Roland-Morris Lower Back Pain Disability Questionnaire
• Neck Disability Index
• Shoulder Pain and Disability Index / SPADI
• Fear-Avoidance Beliefs Questionnaire / FABQ
• Örebro Musculoskeletal Pain Screening Questionnaire
• Pain Self-Efficacy Questionnaire / PSEQ
• Tampa Scale for Kinesiophobia / TSK
• Upper Extremity Functional Index / UEFI
• Oxford Shoulder Instability Score
• Spine Function Index-10
• ACL Quality of Life

FAQs

What does the FAOS measure?

The FAOS measures self-reported foot and ankle pain, symptoms, daily function, sport and recreation function, and quality of life.

How many items are in the FAOS?

The FAOS has 42 items across five subscales.

How is the FAOS scored?

Each subscale is converted to a 0–100 score. A higher score indicates better foot and ankle status.

Is there one total FAOS score?

FAOS is usually interpreted using five separate subscale scores rather than one combined total score.

Does FAOS diagnose a foot or ankle condition?

No. FAOS does not diagnose a condition. It helps measure the client’s perceived symptoms, function and quality-of-life impact.

What is a meaningful change in FAOS?

Meaningful change depends on the population and condition. MIC, MCID, MDC or SEM values should be matched to the client group and measure version where available.

Can FAOS be used for return-to-sport decisions?

FAOS can support return-to-sport reasoning, especially the Sport/Recreation and Quality of Life subscales, but it should not be the only clearance measure.

How often should FAOS be repeated?

It can be repeated at baseline, reassessment, after a training or rehabilitation phase, and at key return-to-activity milestones.

Key Takeaways

• FAOS is a 42-item foot- and ankle-specific patient-reported outcome measure.
• It includes Pain, Symptoms, ADL, Sport/Recreation and Quality of Life subscales.
• Each subscale is scored from 0 to 100.
• Higher scores indicate better perceived foot and ankle status.
• FAOS does not diagnose a condition or clear a client for sport.
• Meaningful change values should be matched to the population and context.
• Published reference values are available, but they should be used as context rather than strict pass/fail standards.
• Measurz should record each subscale, version, completion method, side, baseline comparison, related findings and retest plan.

References

Chen, L., Lyman, S., Do, H., Karlsson, J., Adam, S. P., Young, E., & Ellis, S. J. (2023). Foot and Ankle Outcome Score (FAOS): Reference values from a national representative sample. Foot & Ankle Orthopaedics, 8(4), 24730114231213369. https://doi.org/10.1177/24730114231213369

Larsen, P., Al-Bayati, M., & Elsøe, R. (2021). The Foot and Ankle Outcome Score (FAOS) during early recovery after ankle fracture. Foot & Ankle International, 42(9), 1179–1184. https://doi.org/10.1177/10711007211002811

Roos, E. M., Brandsson, S., & Karlsson, J. (2001). Validation of the Foot and Ankle Outcome Score for ankle ligament reconstruction. Foot & Ankle International, 22(10), 788–794. https://doi.org/10.1177/107110070102201004

Sierevelt, I. N., Zwiers, R., Schats, W., Haverkamp, D., Terwee, C. B., Nolte, P. A., & Kerkhoffs, G. M. M. J. (2018). Measurement properties of the most commonly used foot- and ankle-specific questionnaires: The FFI, FAOS and FAAM. Knee Surgery, Sports Traumatology, Arthroscopy, 26, 2059–2073. https://doi.org/10.1007/s00167-017-4748-7

Tapaninaho, K., Uimonen, M. M., Saarinen, A. J., & Repo, J. P. (2022). Minimal important change for Foot and Ankle Outcome Score (FAOS). Foot and Ankle Surgery, 28(1), 44–48. https://doi.org/10.1016/j.fas.2021.01.009

Yoshida, T. H., et al. (2022). Validation of Foot and Ankle Ability Measure and the Foot and Ankle Outcome Score in individuals with chronic ankle instability. Journal of Orthopaedic Surgery and Research, 17, 113. https://doi.org/10.1186/s13018-022-02925-9