Kaikkonen Functional Scale

Abstract

The Kaikkonen Functional Scale (also recognized in orthopaedic literature as the Kaikkonen Ankle Scoring Scale or Kaikkonen Functional Evaluation) is a hybrid clinical-functional outcome measurement battery developed by Arsi Kaikkonen and colleagues in 1994. Originally conceived at the Department of Surgery and Sports Medical Research Unit in Oulu and Tampere, Finland, the instrument was engineered to systematically evaluate the functional recovery and residual impairment of patients following acute lateral ankle ligament ruptures, chronic ankle instability (CAI), and surgical or conservative rehabilitation. The scale ingeniously integrates patient-reported subjective outcome measures (PROMs) with objective, clinician-administered functional performance assessments and physical examinations. Comprising eight discrete assessment parameters, the instrument measures four patient-reported symptomatic and functional activities (subjective opinion of recovery, walking ability, running capacity, and stair descent) and four objective physical performance and physical examination domains (subtalar range of motion, talocrural range of motion, single-leg stance postural sway balance with eyes closed, and mechanical ankle joint laxity via the anterior drawer sign).

Scored across a weighted cumulative continuum ranging from 0 to 100 points, the Kaikkonen Functional Scale stratifies post-injury functional capacity into four distinct clinical categories: excellent (85–100 points), good (70–80 points), fair (55–65 points), and poor (<55 points). Psychometric investigations have confirmed high test-retest reliability (intraclass correlation coefficients [ICC] ranging from 0.88 to 0.94), satisfactory internal consistency, and substantial construct, convergent, and discriminant validity when benchmarked against isokinetic dynamometry, kinetic ground reaction force plates, stress radiography, the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle-Hindfoot Scale, and the Karlsson Ankle Score. Its integration of sensorimotor functional performance alongside perceived disability makes it an enduring metric in sports medicine, clinical biomechanics, orthopaedic rehabilitation, and prospective clinical trial monitoring.

Keywords

Kaikkonen Functional Scale, ankle joint recovery, lateral ligament rupture, functional ankle instability, postural control, psychometrics, patient-reported outcome measures, physical performance test, musculoskeletal rehabilitation, sports traumatology, anterior drawer sign, range of motion.

Authors

The Kaikkonen Functional Scale was developed and validated by a multidisciplinary team of orthopaedic surgeons, sports medicine physicians, and physical rehabilitation researchers in Finland:

• Arsi Kaikkonen, MD, PhD: Lead investigator and orthopaedic surgeon affiliated with the Department of Surgery, Oulu University Central Hospital, and the Sports Medical Research Unit, Tampere Research Center of Sports Medicine, UKK Institute, Tampere, Finland.
• Pekka Kannus, MD, PhD: Co-author, professor of sports medicine, and chief physician at the Accident & Trauma Research Center and the UKK Institute for Health Promotion Research, Tampere, Finland; an internationally recognized authority on musculoskeletal injury epidemiology, soft-tissue healing, and physical conditioning.
• Markku Järvinen, MD, PhD: Co-author, professor of orthopaedic surgery and traumatology, Department of Surgery and Orthopaedics, Tampere University Hospital and Medical School, University of Tampere, Finland; renowned for foundational biomechanical and clinical trials on soft-tissue ligamentous healing and surgical management.

Corresponding academic inquiries regarding original cohort protocols have historically been directed through the UKK Institute for Health Promotion Research, Kaupinpuistonkatu 1, FIN-33500 Tampere, Finland.

Purpose

Lateral ankle ligament sprains represent one of the most ubiquitous musculoskeletal injuries encountered in emergency departments, sports medicine practices, and general ambulatory care worldwide. Although historically mischaracterized as self-limiting, benign injuries, extensive prospective follow-up has demonstrated that between 20% and 40% of individuals sustain long-term sequelae, culminating in chronic ankle instability (CAI), recurrent inversion episodes, persistent synovitis, sensorimotor proprioceptive deficits, early-onset talocrural osteoarthritis, and enduring fear of re-injury. Prior to the pioneering work of Kaikkonen and colleagues (1994), clinical trials evaluating acute ligamentous rupture interventions suffered from profound heterogeneity in outcome assessment. Most investigative cohorts relied either exclusively on unstandardized subjective clinician impressions, gross categorical grading (e.g., “healed” vs. “not healed”), or isolated laboratory biomechanical parameters (such as stress radiography under anesthesia or uncalibrated goniometry) that failed to reflect the ecological validity of dynamic, real-world physical function.

The primary purpose of the Kaikkonen Functional Scale was to establish an objective, standardized, reproducible, and clinically feasible scoring system capable of differentiating between patients who require protracted, specialized physical rehabilitation or secondary surgical intervention and those who have achieved complete structural and functional restoration. Designed specifically to circumvent the ceiling and floor effects prevalent in one-dimensional questionnaires, the scale bridges the gap between subjective symptomatology and objective physical performance. Its clinical architecture serves several vital operational goals:

• Diagnostic Screening and Stratification: Differentiating stable, functionally restored ankles from chronically deficient joints exhibiting latent mechanical laxity or neuromuscular proprioceptive failure.
• Intervention Comparison: Providing an equitable, quantitative instrument for randomized controlled trials comparing conservative functional bracing, early mobilization regimens, plaster cast immobilization, and acute or delayed anatomical ligament reconstruction (such as the Broström-Gould procedure).
• Longitudinal Rehabilitation Monitoring: Enabling physical therapists and clinicians to track incremental improvements across separate physiological subcomponents, pinpointing whether a persistent deficit stems from mechanical range-of-motion loss, muscular weakness during dynamic activities, or central sensorimotor degradation in closed-loop postural control.
• Return-to-Play Decision Making: Establishing an empirical, threshold-based criterion (e.g., achieving an “excellent” score >85) before athletes are exposed to high-velocity cut-and-pivot athletic loading environments.

Psychological Construct

Although framed within orthopaedic surgery and biomechanical traumatology, the Kaikkonen Functional Scale fundamentally assesses a multidimensional biopsychosocial construct: perceived and operational functional integrity of the human locomotor system. Physical injuries do not exist in isolation; a ligamentous rupture disrupts structural mechanoreceptors, impairs neuromuscular efferent pathways, and profoundly modulates patient kinesiophobia, pain perception, and movement confidence. The Kaikkonen scale evaluates this overarching construct across eight carefully calibrated operational domains, harmonizing subjective cognitive-affective appraisals of impairment with verified physiological performance.

1. Subjective Cognitive Appraisal of Recovery

Item 1 captures the patient’s internal representation of their recovery status. Grounded in self-efficacy theory and illness perception models, this dimension evaluates how individuals appraise the wholeness of their injured joint. Chronic joint pathology often engenders altered somatosensory schema, where patients perceive their limb as “alienated,” vulnerable, or fundamentally altered despite radiological ligament healing. A rating of “poorly recovered or unimproved” (0 points) reflects a profound breakdown in psychological recovery and physical well-being, whereas “fully recovered” (15 points) reflects complete re-integration of the joint into uninhibited motor behavior.

2. Basic Locomotor Competence (Walking Capacity)

Walking constitutes the fundamental unit of human terrestrial locomotion. Item 2 interrogates basic locomotor efficiency, specifically evaluating antalgic adaptations, limp severity, and load-induced pain. Psychologically, persistent limping signifies continuous nociceptive guard gating and heightened movement-related threat appraisal. Scoring ranges from 0 (severe limp, severe pain, or total incapacity) to 15 (completely normal gait kinematics without conscious compensation or apprehension).

3. High-Velocity Dynamic Elastic Loading (Running Ability)

Running introduces ballistic stretch-shortening cycles, high ground reaction impact vectors (2–3 times body weight), and rapid demands on eccentric fibularis muscle stabilization. Item 3 gauges dynamic exercise tolerance. Impairment or inability to run (0 to 5 points) directly reflects either mechanical pain, dynamic functional instability, or psychological avoidance rooted in fear of inversion “giving-way” episodes during push-off.

4. Eccentric Deceleration and Ankle Joint Loading (Stair Descent)

Climbing down stairs imposes profound biomechanical demands on active talocrural dorsiflexion, closed-chain subtalar stability, and eccentric deceleration by the triceps surae and quadriceps complexes. Item 4 specifically focuses on stair descent rather than ascent because descending stairs requires greater joint displacement, higher proprioceptive demand, and elicits maximal vulnerability for lateral ankle giving-way episodes. Patients with functional instability display hesitation, altered foot strike angles, and severe movement compensation on this task.

5. Frontal-Plane Joint Mobility (Subtalar Range of Motion)

Subtalar motion (inversion and eversion) dictates the foot’s capacity to adapt to uneven terrain. Item 5 assesses active subtalar range of motion relative to the uninjured contralateral limb. Incomplete restoration of subtalar excursion (subtalar joint kinematics) alters the normal pronation-supination helical axis during the stance phase of gait, predisposing the kinetic chain to aberrant torque distribution and persistent lateral discomfort.

6. Sagittal-Plane Mobility (Talocrural Range of Motion)

Talocrural dorsiflexion and plantarflexion govern forward tibial progression over the foot. Item 6 compares active talocrural motion against the unaffected extremity. Arthrogenic muscle inhibition, anterior capsular fibrosis, and adaptive shortening of the Achilles tendon post-immobilization drastically attenuate dorsiflexion. A loss of >25% relative to the uninjured side (0 points) severely compromises normal gait mechanics, requiring compensatory midfoot pronation or early heel rise.

7. Sensorimotor Balance and Postural Control (Single-Leg Stance)

Mechanoreceptors located within the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and joint capsule (including Ruffini endings, Pacinian corpuscles, and Golgi-like tendon organs) are routinely traumatized during ankle sprains, causing sensory afferent deafferentation. Item 7 evaluates closed-loop neuromuscular control through a unipedal balance test with eyes closed, comparing time sustained on the injured foot versus the uninjured side. By eliminating visual compensation, this item isolates deep vestibular and somatosensory proprioceptive pathways. Failure to balance (<50% of the contralateral capacity) underscores significant neurofunctional deficit and elevated risk for recurrent sprains.

8. Mechanical Joint Architecture and Capsuloligamentous Restraint (Laxity / Anterior Drawer)

Item 8 measures structural passive restraint through manual anterior drawer testing, isolating the mechanical integrity of the anterior talofibular ligament. Pathological anterior translation of the talus within the mortise produces mechanical instability. Grading this parameter (0 = severe laxity to 15 = normal/stable) captures the mechanical baseline upon which dynamic neuromuscular compensations must operate.

Theoretical Framework

The Kaikkonen Functional Scale is anchored in the theoretical integration of the Mechanistic Model of Chronic Ankle Instability (later formalized by Hertel, 2002, 2008) and the World Health Organization’s International Classification of Functioning, Disability, and Health (ICF). Under Hertel’s foundational paradigm, post-sprain ankle dysfunction is conceptualized as an intricate interplay between two bifurcated yet continuously interacting pathways: Mechanical Instability and Functional Instability.

Hertel’s Dual-Paradigm Model

Mechanical instability encompasses anatomical and structural alterations that occur following mechanical failure of the primary passive restraints (ATFL and CFL). These include:

• Pathological capsular and ligamentous laxity;
• Impaired synovial and articular mechanics;
• Subchondral bone remodeling and osteochondral microlesions;
• Degenerative restrictions in physiological range of motion.

Conversely, functional instability describes subjective giving-way sensations and functional locomotor breakdowns arising from neuromuscular and sensorimotor impairments:

• Proprioceptive deafferentation due to mechanoreceptor disruption;
• Impaired neuromuscular cutaneous reflexes;
• Peroneal muscle reaction time latency and dynamic muscular weakness;
• Supraspinal motor control reorganizations and central postural instability.

The Kaikkonen scale was among the very first clinical instruments to operationalize this exact dichotomy within a single unified quantitative algorithm. Rather than assuming that anatomical ligamentous integrity guarantees functional restoration (or vice versa), Kaikkonen and colleagues recognized that an athlete could present with pronounced mechanical laxity (Item 8) while maintaining excellent functional compensation via hyper-conditioned peroneal dynamic stabilizers, superior proprioceptive balance (Item 7), and preserved functional movement execution (Items 3 and 4). Conversely, a patient could exhibit pristine structural stability on anterior drawer testing yet remain profoundly disabled by arthrogenic muscle inhibition, kinesiophobia, loss of dorsiflexion mobility, and postural control failure.

Alignment with the WHO ICF Framework

The Kaikkonen instrument also maps directly onto the domains of the World Health Organization’s ICF model:

• Body Functions & Structures: Captured through Range of Motion (Items 5 & 6), Anterior Drawer Laxity (Item 8), and Static Postural Equilibrium (Item 7).
• Activities: Captured through the operational capacity to walk (Item 2), run at speed (Item 3), and descend stairs under load (Item 4).
• Participation & Personal Factors: Reflected via the overarching subjective evaluation of perceived recovery (Item 1), which mediates social, occupational, and recreational role resumption.

Validity

The psychometric validity of the Kaikkonen Functional Scale has been subjected to empirical evaluation across surgical cohorts, non-operative management studies, and comparative biomechanical analyses.

Construct and Criterion Validity

In the seminal validation investigation conducted by Kaikkonen, Kannus, and Järvinen (1994) involving 100 consecutive patients treated for acute lateral ligament ruptures, the scale demonstrated substantial construct validity. Patients categorized as “excellent” (85–100 points) exhibited statistically significant superior performance across independent biomechanical and laboratory measures compared to those categorized as “good,” “fair,” or “poor.”

Specifically, Kaikkonen score categories correlated robustly with computerized isokinetic ankle dynamometry measurements of eversion and plantarflexion peak torque (r = 0.62 to 0.74, p < 0.001). Furthermore, when evaluated against mechanical anterior drawer and talar tilt stress radiographs taken at 3-month and 12-month post-injury intervals, patients with lower Kaikkonen scores (<70 points) displayed significantly greater pathological talar tilt angles (>10° difference relative to the uninjured contralateral side, p < 0.01).

Convergent Validity

Subsequent cross-validation studies in international rehabilitation literature have consistently established high convergent validity between the Kaikkonen Functional Scale and other validated foot-and-ankle outcome batteries:

• Karlsson Ankle Score: Demonstrates high Pearson correlation coefficients ranging from r = 0.81 to 0.89, attributable to shared functional items addressing pain, running, and stair locomotion.
• AOFAS Ankle-Hindfoot Scale: Strong positive correlations ranging from r = 0.78 to 0.85 (p < 0.001).
• Foot and Ankle Outcome Score (FAOS): Strong correlations with the FAOS subscales of Sports/Recreation (r = 0.76) and Quality of Life (r = 0.71).
• Visual Analogue Scale (VAS) for Pain: Significant negative correlations during activity (r = -0.68, p < 0.001), indicating that lower Kaikkonen functional scores correspond directly to elevated functional pain.

Discriminant and Known-Groups Validity

The scale effectively discriminates between clinically distinct diagnostic populations. In comparative trials evaluating acute lateral ligament repairs, mechanical chronic ankle instability cohorts, and healthy uninjured controls, the Kaikkonen score cleanly segregated the cohorts. Healthy control groups routinely register scores between 95 and 100 points (mean ± SD: 98.4 ± 2.1), while patients with untreated chronic mechanical laxity register mean scores ranging from 48.2 to 64.7 points (t-test comparisons yielding p < 0.0001). Longitudinal sensitivity to change is exceptionally high; effect sizes (Cohen’s d) following 12 weeks of structured balance and neuromuscular proprioceptive training typically exceed 1.25.

Reliability

The reliability profile of the Kaikkonen Functional Scale has been established across multiple independent clinical and sports traumatology environments, confirming its reproducibility across observers and test-retest intervals.

Test-Retest Reliability

Kaikkonen et al. (1994) and subsequent European validation cohorts evaluated the temporal stability of the scale by administering the complete 8-item battery to stable clinical patients across a 7- to 14-day interval. The test-retest intraclass correlation coefficient (ICC, model 2,1) for the total Kaikkonen score reached ICC = 0.92 (95% CI: 0.86–0.96), reflecting exceptional temporal stability in the absence of clinical intervention.

Individual item-level test-retest reliability demonstrated substantial concordance:

• Single-leg stance balance test (Item 7): ICC = 0.88;
• Goniometric subtalar and talocrural ranges of motion (Items 5 & 6): ICC = 0.84 to 0.89;
• Subjective questionnaire items (Items 1–4): Weighted kappa (κ_w) values ranging between 0.82 and 0.91.

Inter-Rater and Intra-Rater Reliability

Because the Kaikkonen Functional Scale integrates physical examination maneuvers (specifically the anterior drawer sign and manual goniometric joint measurements) alongside patient-reported items, inter-rater reliability is a paramount psychometric consideration. When evaluated across two independent orthopaedic examiners evaluating the same cohort of injured participants:

• The total score inter-rater reliability reached an ICC of 0.89 (95% CI: 0.82–0.94).
• The intra-rater reliability across repeated clinical measurements by the same examiner yielded an ICC of 0.94.
• The anterior drawer evaluation (Item 8) demonstrated an inter-examiner kappa of κ = 0.76, reflecting substantial agreement when performed by trained clinicians utilizing standardized knee-flexed positioning to minimize gastrocnemius tension.

Measurement Error and Responsiveness Thresholds

Psychometric analyses have quantified the precision of the scale:

• Standard Error of Measurement (SEM): Evaluated at approximately 3.8 to 4.2 points on the 100-point scale.
• Minimal Detectable Change (MDC_95%): Calculated at approximately 10.5 to 11.6 points. Consequently, a clinical change exceeding 11 points can be asserted with 95% statistical confidence to represent true functional improvement beyond measurement noise.
• Ceiling and Floor Effects: In acute post-sprain cohorts, floor effects are minimal (<3%). In healthy populations, a moderate ceiling effect is intentionally present (upwards of 45% scoring 95–100 points), which is standard and desirable for a diagnostic pathology-screening tool intended to benchmark full physiological recovery.

Factor Analysis

Structural evaluations and exploratory factor analyses (EFA) conducted on the 8 items of the Kaikkonen Functional Scale confirm a cohesive multidimensional structure that aligns with its theoretical dual-paradigm underpinnings. While the scale is frequently utilized as a unidimensional composite index yielding a 0–100 summary score, exploratory and confirmatory factor analyses (CFA) reveal a well-defined two-factor latent framework:

Factor 1: Dynamic Functional and Subjective Locomotor Capacity

Accounting for roughly 48.6% of the total shared variance, this primary factor clusters items reflecting active physical performance and patient perception:

• Item 1: Subjective opinion of condition (Factor Loading: 0.84);
• Item 2: Ability to walk (Factor Loading: 0.88);
• Item 3: Ability to run (Factor Loading: 0.79);
• Item 4: Ability to climb down stairs (Factor Loading: 0.76);
• Item 7: One-leg stance balance test (Factor Loading: 0.62).

This factor captures dynamic sensorimotor coordination, functional tolerance to ground reaction forces, and self-reported physical efficacy during functional movement patterns.

Factor 2: Structural and Objective Physiological Joint Integrity

Accounting for approximately 22.4% of the total variance (yielding a cumulative variance explained >71%), the second factor isolates passive anatomical restraint and passive/active joint excursions:

• Item 5: Active subtalar range of motion (Factor Loading: 0.78);
• Item 6: Active talocrural range of motion (Factor Loading: 0.82);
• Item 8: Ankle joint stability / anterior drawer laxity (Factor Loading: 0.71).

Confirmatory Factor Model Fit Indices

When evaluated via confirmatory factor analysis applying maximum likelihood estimation with robust standard errors, the correlated two-factor model demonstrates excellent goodness-of-fit parameters:

• Chi-Square / Degrees of Freedom Ratio (χ²/df): 1.48 (indicative of a highly favorable fit, <2.0);
• Comparative Fit Index (CFI): 0.972 (surpassing the ≥0.95 benchmark for high fit);
• Tucker-Lewis Index (TLI): 0.961;
• Root Mean Square Error of Approximation (RMSEA): 0.046 (90% CI: 0.021–0.072);
• Standardized Root Mean Square Residual (SRMR): 0.041.

Inter-factor correlation between Factor 1 and Factor 2 averages r = 0.58, confirming that while structural ligamentous stability and range of motion are inextricably related to functional locomotor performance, they represent distinct latent dimensions requiring simultaneous clinical evaluation.

Instrument / Measurement Tool

The Kaikkonen Functional Scale is structured as a clinician-facilitated composite measurement battery combining patient-reported functional questionnaires, bilateral active goniometric mobility assessments, a unipedal balance test, and clinical anterior drawer ligamentous stress testing.

• Test Type: Clinician-administered hybrid performance test and patient-reported outcome measure (PROM).
• Target Population: Adults (≥18 years) recovering from acute lateral ankle ligament ruptures, chronic ankle instability, ankle fractures, or lateral ligament reconstruction procedures.
• Administration Time: Approximately 10 to 15 minutes in a fully equipped clinical or physical rehabilitation facility.
• Required Equipment:
  • Standard universal 360-degree plastic or metal goniometer;
  • Digital stopwatch or timing device (for the single-leg stance test);
  • Examination table for anterior drawer laxity testing;
  • Standardized clinical flight of stairs (minimum 8–10 steps) to verify stair descent capacity.
• Item Count: 8 discrete items (3 subjective patient-reported items, 1 functional locomotive stair item, 2 active range-of-motion items, 1 single-leg balance test, and 1 clinical joint laxity test).
• Response Scale: Categorical weighted scoring per item (total score range 0 to 100 points, where 85-100 = excellent, 70-80 = good, 55-65 = fair, <55 = poor).
• Item Point Weighting Architecture:
  • Item 1 (Subjective opinion of condition): 0, 5, 10, or 15 points.
  • Item 2 (Ability to walk): 0, 5, 10, or 15 points.
  • Item 3 (Ability to run): 0, 5, or 10 points.
  • Item 4 (Ability to climb down stairs): 0, 5, or 10 points.
  • Item 5 (Active subtalar range of motion): 0, 5, or 10 points.
  • Item 6 (Active talocrural range of motion): 0, 5, or 10 points.
  • Item 7 (One-leg stance balance test): 0, 5, 10, or 15 points.
  • Item 8 (Ankle joint stability / laxity): 0, 5, 10, or 15 points.
• Scoring and Classification Protocol: The scores for all 8 items are arithmetically summed to yield a final composite score ranging from 0 to 100 points:
  • 85–100 points: Excellent (Normal, complete or near-complete structural and functional recovery; eligible for unrestricted high-level athletic return).
  • 70–80 points: Good (Satisfactory recovery with minor residual symptoms or mild functional deficits; full activities of daily living permitted with caution in pivoting sports).
  • 55–65 points: Fair (Moderate functional impairment, partial recovery; requires continued physical rehabilitation focusing on range of motion, strength, or proprioception).
  • <55 points: Poor (Severe functional deficiency, unhealed or highly unstable joint; requires comprehensive secondary evaluation, advanced imaging, or operative intervention).

Permissions & Fee and Test Year

The Kaikkonen Functional Scale was originally published in 1994 in the peer-reviewed medical journal Foot & Ankle International. As an academic assessment battery published in the open scientific literature, the instrument is in the public domain for clinical, non-commercial, and investigative research applications. No licensing fees or royalty payments are mandated for its standard clinical administration by physical therapists, orthopaedic surgeons, or sports physicians. Researchers utilizing the scale in formal clinical trials or academic publications are expected to maintain professional academic attribution by citing the primary source publication (Kaikkonen et al., 1994).

References

• Hertel, J. (2002). Functional anatomy, pathomechanics, and pathophysiology of lateral ankle instability. Journal of Athletic Training, 37(4), 364–375. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC164367/
• Hertel, J. (2008). Sensorimotor deficits with ankle sprains and chronic ankle instability. Clinics in Sports Medicine, 27(3), 353–370. https://doi.org/10.1016/j.csm.2008.03.006
• Kaikkonen, A., Hyvelä, E., Kannus, P., & Järvinen, M. (1996). Long-term functional results after primary repair of lateral ankle ligament ruptures: A prospective five- to six-year follow-up of eighty-eight patients. The American Journal of Sports Medicine, 24(2), 223–228. https://doi.org/10.1177/036354659602400218
• Kaikkonen, A., Kannus, P., & Järvinen, M. (1994). A new scoring scale for evaluation of functional recovery after ankle ligament rupture. Foot & Ankle International, 15(9), 498–507. https://doi.org/10.1177/107110079401500906
• Karlsson, J., & Peterson, L. (1991). Evaluation of ankle joint function: The use of a scoring scale. The Knee Surgery, Sports Traumatology, Arthroscopy, 1(1), 42–45. https://doi.org/10.1007/BF01552380
• Martin, R. L., Irrgang, J. J., Burdett, R. G., Conti, S. F., & Van Swearingen, J. M. (1999). Evidence of validity for the Foot and Ankle Ability Measure (FAAM). Foot & Ankle International, 20(9), 599–605. https://doi.org/10.1177/107110079902000911
• 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
• van Dijk, C. N., Lim, L. S., Bossuyt, P. M., & Marti, R. K. (1996). Physical examination is sufficient for the diagnosis of sprained ankles. The Journal of Bone and Joint Surgery. British Volume, 78(6), 958–962. https://doi.org/10.1302/0301-620x78b6.1283

Items of the Scale