Study of the AxisBoard Single-Leg Balance Board in Adults With Lateral Ankle Sprain

The goal of this study is to learn whether a 28-day home exercise program using the AxisBoard Single-Leg Balance Board improves ankle function in adults who are still having symptoms 6 weeks to 6 months after a lateral (outer) ankle sprain. The study will also look at the safety and ease of use of the AxisBoard. The main questions it aims to answer are: * Does ankle function in daily activities, measured with the Foot and Ankle Ability Measure Activities of Daily Living (FAAM-ADL) subscale, improve from the start of the study to Day 28? * How do ankle pain, stability, balance, stiffness, strength, confidence, and return to activity change over the 28 days, and how satisfied are participants with the AxisBoard? There is no comparison group. Each participant's results will be compared with their own results at the start of the study. Participants will: * Complete screening and all study visits virtually, by video call, from home * Use the AxisBoard at home for 10 minutes once a day for 28 days, following a standardized exercise program * Complete a short daily electronic diary about pain, stiffness, ankle stability, and AxisBoard use * Attend virtual study visits at the start of the study and on Days 3, 7, 14, and 28 for questionnaires and recorded balance and movement tests