Development and reliability of the ankle instability instrument

Area of Science:

• Sports Medicine
• Orthopedics
• Rehabilitation Science

Background:

• Functional ankle instability lacks a consistent definition, often relying on factors like recurrent sprains or a feeling of 'giving way'.
• Developing a standardized assessment framework is crucial for accurately identifying and managing this condition.

Purpose of the Study:

• To introduce the Ankle Instability Instrument, a novel tool for assessing functional ankle instability.
• To rigorously evaluate the reliability and internal consistency of this new instrument.

Main Methods:

• The Ankle Instability Instrument was administered to college students on two separate occasions, approximately one week apart.
• Test-retest reliability was assessed using intraclass correlation coefficients, and internal consistency was determined via Cronbach's alpha for the 12-item instrument.

Main Results:

• Exploratory factor analysis refined the instrument to 12 items, identifying 3 key factors accounting for 50% of the variance.
• The instrument demonstrated high test-retest reliability (overall ICC = .95) and excellent internal consistency (overall Cronbach's alpha = .89).
• Individual factors showed strong reliability: factor 1 (.92), factor 2 (.87), and factor 3 (.81).

Conclusions:

• The Ankle Instability Instrument provides a reliable and objective method for identifying functional ankle instability.
• Self-reported ankle symptoms, as captured by this instrument, are a feasible and appropriate measure for assessing instability.
• The instrument's three factors offer valuable insights into the components of functional ankle instability, aiding clinicians and researchers.