Neurocognitive Ankle Training for Instability to Optimize Neuromusculoskeletal Outcomes (NATION)

Inclusion Criteria: * Physically active and engage in regular exercise/training * 18-44 years old (accounts for 86% of the individuals deployed in recent military conflicts) * Answer "yes" to Question 1 (i.e., have you ever sprained an ankle?) on the Ankle Instability Instrument * Answer "yes" to any four of the remaining Ankle Instability Instrument questions * Score \<24 on the Cumberland Ankle Instability Tool * Report at least two episodes of the ankle "giving way" in the last six months * Access to a functional email address and internet for completion of health and Service member outcomes * Ability to provide informed consent Exclusion Criteria: * Unable to read or comprehend the English language. * An ankle sprain within the last six (≤6) weeks that resulted in altered or missed physical activity for one or more (≥1) consecutive days. * History of ankle surgery. * History of lower extremity fracture in the last year or history of fracture that required fixation. * Any peripheral neuropathies or other health conditions/current musculoskeletal injuries that may influence balance. * Pregnant females (will be eligible for participation in the study after delivery of the baby and medical clearance by a qualified and licensed healthcare provider).