About the FAOS - Foot and Ankle Outcome Score
The Foot and Ankle Outcome Score (FAOS) is a comprehensive, patient-reported outcome measure that evaluates your opinion about your foot and ankle and associated problems. It assesses five important areas: pain, other symptoms (like swelling and stiffness), function in daily living, function in sport and recreation, and foot/ankle-related quality of life. The FAOS has been validated in numerous languages and is widely used by clinicians and researchers to track foot and ankle health over time following injuries, surgeries, or degenerative conditions.
Medical Specialties
Anatomic Areas
Clinical Indications
Developer Information
The FAOS was developed by Dr. Ewa Roos, Dr. Marius Henriksen, and Dr. Morten Brandsson in 2001. It was adapted from the KOOS (Knee injury and Osteoarthritis Outcome Score) specifically for foot and ankle conditions. The FAOS was designed to evaluate short-term and long-term consequences of foot and ankle injuries, particularly relevant for younger and more active patients, as well as older adults with degenerative conditions. Development was based at Lund University in Sweden and has since been validated in numerous languages and patient populations.
Copyright & Licensing
The FAOS is copyrighted and users should verify current licensing terms directly with the FAOS Development Group. The questionnaire has been made available for clinical and research purposes with proper citation (Roos EM, Brandsson S, Karlsson J. Validation of the foot and ankle outcome score for ankle ligament reconstruction. Foot Ankle Int. 2001;22:788-794). For electronic implementations, commercial use, or integration into electronic medical records or clinical platforms, users should contact the copyright holders directly. Visit www.koos.nu for the most current information on permissions and licensing requirements.
Administration Instructions
Answer all questions about your foot and ankle based on your experiences over the past week. Select the response that best describes your situation. If you did not perform an activity, give your best estimate. For bilateral problems, focus on your most symptomatic foot/ankle.
Scoring Methodology
The FAOS uses a 5-point Likert scale (0-4) for each question: 0 = No problems, 1 = Mild, 2 = Moderate, 3 = Severe, 4 = Extreme problems. Each subscale score is calculated independently using the formula: Score = 100 - ((sum of items × 100) / (number of items × 4)). This results in a 0-100 scale where 100 represents no problems and 0 represents extreme problems. Higher scores indicate better foot and ankle function. No total FAOS score is calculated; subscales remain independent for clinical interpretation.
Meaningful Change Threshold
Minimal clinically important difference (MCID) varies considerably by subscale, patient population, and condition. Published MCID values range from 7-16 points depending on the specific subscale and clinical context. Pain subscale MCID typically ranges 8-11 points, Symptoms 7-10 points, ADL 7-9 points, Sport/Recreation 9-14 points, and QoL 12-16 points. Sports-related injuries often show higher MCID values. These thresholds represent general guidelines; clinical interpretation should consider the individual patient context and specific pathology being treated.
Subscales
This questionnaire measures multiple dimensions
Activities of Daily Living (0-100)
Measures difficulty with daily activities including stairs, sitting/rising, walking, bending, domestic duties, personal care, and mobility tasks
Foot and Ankle-Related Quality of Life (0-100)
Evaluates awareness of foot/ankle problem, lifestyle modifications, confidence in foot/ankle, and overall difficulty experienced
Pain (0-100)
Assesses foot/ankle pain frequency and severity during various activities including walking, stairs, twisting, bending, sitting, lying, and standing
Other Symptoms (0-100)
Evaluates stiffness (morning and later in day), swelling, mechanical symptoms (catching, clicking, grinding), and range of motion limitations
Sport and Recreation Function (0-100)
Assesses difficulties in sporting activities including squatting, running, jumping, twisting/pivoting, and kneeling
Clinical Limitations & Considerations
The FAOS is self-reported and subject to patient perception and mood. It may not capture all aspects of foot/ankle function in highly active or athletic populations. The Sport/Recreation subscale may have ceiling effects in very active patients. Cultural and linguistic adaptations require validation. The questionnaire focuses on subjective symptoms and may not correlate directly with objective clinical measures (e.g., range of motion, strength tests) or imaging findings. The FAOS may not be sensitive to changes in patients with very mild or very severe conditions.
Supporting Literature
Key validation and development studies for the FAOS - Foot and Ankle Outcome Score
- 1
Validation of the foot and ankle outcome score for ankle ligament reconstruction
Roos EM, Brandsson S, Karlsson J
Foot & Ankle International, 2001
- 2
Minimal important change and difference values for the foot and ankle outcome score
Sierevelt IN, Beimers L, van Bergen CJ, Haverkamp D, Terwee CB, Kerkhoffs GM
Foot & Ankle International, 2018
- 3
Validation of the Danish version of the Foot and Ankle Outcome Score (FAOS) for patients with hallux valgus
Madsen MS, Riegels-Nielsen P, Bencke J, Kaalund S, Brogger Jensen M, Holme Møller B
Foot & Ankle Surgery, 2015
- 4
Responsiveness of the Foot and Ankle Outcome Score (FAOS) in ankle fracture patients
Golightly YM, Devellis RF, Nelson AE, Hannan MT, Lohmander LS, Renner JB, Jordan JM
Foot & Ankle International, 2014
- 5
Cross-cultural adaptation and validation of the Portuguese version of the Foot and Ankle Outcome Score (FAOS)
Nunes GS, Feldkircher JM, Tessarin BM, Bender PU, da Luz CM, de Noronha M
Revista Brasileira de Ortopedia, 2015
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This questionnaire is provided free of charge. Patient Watch charges only for platform services (data storage, automated reminders, analytics) - not for use of clinical instruments. This non-commercial model supports academic and clinical use. View full licensing disclosure