Cross-cultural adaptation, reliability, and validity of the Sinhala version of the Cumberland Ankle Instability Tool: an instrument for measuring chronic ankle instability in Sri Lanka.

Purpose: To develop the Sinhala version of the Cumberland Ankle Instability Tool (CAIT-Sin) and evaluate its validity and reliability in native Sinhala speakers.

Methods: The CAIT was translated and cross-culturally adapted into Sinhala, using a forward-backward translation method. CAIT-Sin, Karlsson score, and visual analog scale (VAS) were filled out by 156 university athletes and students with and without ankle instabilities, in order to test internal consistency, test-retest reliability, criterion validity, floor and ceiling effect, and discriminative ability of the CAIT-Sin.