Test-retest reliability of ankle range of motion, proprioception, and balance for symptom and gender effects in individuals with chronic ankle instability

Objectives: To determine the reliability of the commonly used musculoskeletal assessments in individuals with chronic ankle instability (CAI). Design: Within and between-days test-retest reliability. Setting: University laboratory. Participants: Twenty-four individuals with unilateral CAI. Method: For both sides, ankle dorsiflexion range of motion (DFROM) was assessed by a goniometer and weight-bearing lunge test (WBLT), proprioception by the active movement extent discrimination apparatus (AMEDA), and balance by the Star Excursion Balance Test with anterior (SEBTA), posteromedial (SEBTPM) and posterolateral (SEBTPL) components. All measures were taken at enrollment, after 30 min and one week later. Results: For the asymptomatic side, all assessments demonstrated good to excellent reliability, with ICCs _(3,1) between 0.8 and 0.96. On the symptomatic side, WBLT, SEBTA and SEBTPM showed excellent reliability, with ICCs _(3,1) above 0.90, while SEBTPL, goniometer and AMEDA showed moderate reliability, with the 95% CI of the ICCs _(3,1) crossing 0.5. Three-way repeated measures ANOVA showed a side main effect, with asymptomatic worse, for WBLT (F = 16.9, p < 0.001) and SEBTA (F = 5.4, p = 0.03); an overall improving time main effect for SEBTPL (F = 6.9, p = 0.02). Neither a gender main effect nor any interaction effect was found. Conclusions: WBLT, SEBTA and SEBTPM can be strongly recommended for measuring ankle dorsiflexion mobility and dynamic balance for both sides of individuals with unilateral CAI, while only WBLT can be used for side-to-side comparison. The application of a goniometer to measure DFROM, SEBTPL or AMEDA should be done cautiously for this specific cohort, considering their poor to good reliability for the symptomatic side.