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).