Patient-reported outcome measure
FADI Calculator
Foot and Ankle Disability Index
The Foot and Ankle Disability Index is a patient-reported questionnaire of 26 scored items — 22 activities and 4 pain items, each rated 0 to 4 for a maximum of 104 — with an optional 8-item sports subscale out of 32, where a higher score means less disability.
What the FADI score means
FADI totals run from 0 to 100, where a higher score is better. No severity bands are shown because no cut-offs have been published that we can verify — read the total against the source studies and your own protocol, as described below.
How the score is calculated
Stated in full so the calculation can be independently checked, and reproduced by hand if needed.
Each of the 22 activity items is rated from unable to do (0) through extremely difficult (1), moderately difficult (2) and slightly difficult (3) to no difficulty at all (4). Each of the four pain items is rated from unbearable (0) through severe (1), moderate (2) and mild (3) to no pain (4). The 26 scores are added to a total out of 104, where 0 is the maximum disability and 104 is none; the calculator reports this as a percentage of 104. The optional sports subscale has eight items scored 0 to 4 on the same difficulty scale and is out of 32, and is reported separately as a percentage. A higher score means less disability. The activity and sports subscales can each be scored on their own.
Missing data
No missing-data rule has been published, so a total is shown only when every item of that score is answered. A prorated score is not comparable with published figures.
Instrument profile
- Developer
- Robroy L. Martin and colleagues
- Institution
- University of Pittsburgh, United States
- First published
- 1999
- Custodian
- No active custodian known to us
- Items
- 34
- Response format
- Five response options per item, scored 4 to 0
- Score range
- 0 to 100
- Direction
- Higher score = better
- Recall period
- The past week
- Completion time
- About 5 minutes
- Age range
- Adults
- Regions
- Foot & Ankle
- Conditions
- Chronic ankle instability, Ankle sprain, Lateral ankle sprain, Ankle instability
- Procedures
- Lateral ankle ligament reconstruction, Ankle rehabilitation
- Languages
- English
- Test–retest (ICC)
- Reliability and sensitivity were examined in people with chronic ankle instability by Hale and Hertel in 2005; we have not reproduced their figures here because we could not check them against the paper.
- Validity
- Developed for chronic ankle instability and widely used in that population. It was the basis for the Foot and Ankle Ability Measure.
- Responsiveness
- Scores rise after rehabilitation in people with chronic ankle instability. No minimal clinically important difference is shown here because we could not verify a published value.
- Ceiling effect
- Likely in recreationally active people, which is why the separate sports subscale exists.
When to use the FADI
Well suited to
- Reading and comparing the chronic ankle instability literature, much of which reports FADI and FADI sport scores.
- Continuing a series or rehabilitation programme that collected the FADI from the start.
Limitations and poor fits
- Choosing a primary outcome for a new study: the Foot and Ankle Ability Measure was developed from the FADI and has fuller psychometric evidence.
- Judging whether an individual patient has improved meaningfully, since no minimal clinically important difference is shown here.
- Forefoot problems such as hallux valgus, which the index was not designed to measure.
FADI compared with other instruments
Instruments measuring a related construct, with the practical difference between them.
| Instrument | Items | Range | What it adds |
|---|---|---|---|
| FAAM | 29 | 0–100 | The FAAM is a 29-item patient-reported questionnaire for musculoskeletal disorders of the leg, foot and ankle that produces two separate subscale scores — Activities of Daily Living from 21 items and Sports from 8 items — each expressed from 0% (unable to perform the listed activities) to 100% (no limitation). |
| FAOS | 42 | 0–100 | The FAOS is a 42-item patient-reported questionnaire adapted from the KOOS that scores foot and ankle problems as five separate subscales — Symptoms, Pain, Activities of Daily Living, Sport and Recreation, and Quality of Life — each from 0 (extreme problems) to 100 (no problems). |
| AOFAS Ankle-Hindfoot | 9 | 0–100 | The AOFAS Ankle-Hindfoot Scale is a 100-point clinician-administered rating combining 40 points for pain, 50 for function across seven items and 10 for alignment — and although it remains the most-reported outcome in the foot and ankle literature, the society that published it withdrew its endorsement in 2011 because it was never validated. |
Copyright and permitted use
Published openly because it is the question every clinician and researcher asks before using an instrument, and almost nobody answers it.
The index is circulated freely in clinics and used throughout the ankle instability literature, and we know of no licensing programme. We have not asked the developers for written permission, so we cannot say it is free of copyright; if a rights holder objects, the item wording will be removed and the page reduced to a profile.
References
- Martin RL, Burdett RG, Irrgang JJ. Development of the Foot and Ankle Disability Index (FADI). Journal of Orthopaedic and Sports Physical Therapy. 1999.
- Hale SA, Hertel J. Reliability and sensitivity of the Foot and Ankle Disability Index in subjects with chronic ankle instability. Journal of Athletic Training. 2005.PMID 15902322
Editorial status
Not yet reviewedQueued for clinical review by Sam Tuffun, PT, DPT. Sign-off has not taken place — this is a placeholder assignment, not a completed review.