OBJECTIVES: 1. To determine whether individuals with chronic ankle instability (CAI) have lower proprioception sensitivity scores from a test on the Active Movement Extent Discrimination Apparatus (AMEDA). 2. To determine whether individuals with CAI can improve proprioception sensitivity scores with repeated active movement testing using the AMEDA. 3. To assess the test-retest reliability of the AMEDA. DESIGN: A cohort study comparing those with CAI or healthy ankles. SETTING: University clinical laboratory. PARTICIPANTS: 61 healthy university students, 36 with CAI, 25 with stable ankles. MAIN OUTCOME MEASURES: A 2-way ANOVA was conducted to compare performance of CAI and stable ankle groups, over 3 test repetitions on the AMEDA. The reliability intra-class correlation coefficient (ICC) was obtained for test repetitions. RESULTS: The scores improved in both groups when the AMEDA test was repeated (p = <0.001). The rates of improvement in proprioception test scores differed, with the CAI group showing a slower learning rate than the stable ankle group (p = 0.047). The ICC for the whole group across the three trials was 0.80 (95% CI = 0.69 to 0.87, p = <0.001). CONCLUSIONS: CAI participants improve their proprioception scores more slowly upon repeated AMEDA testing, suggesting differences in learning strategies.