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

The purpose of this study is to examine the effectiveness of a novel ankle rehabilitation protocol on improving clinical and health outcomes in physically active individuals with chronic ankle instability (CAI). Our central hypothesis is NATION, a novel rehabilitation intervention that includes neurocognitive tasks, will improve overall health and function, and reduce lower extremity musculoskeletal injury in physically active individuals with CAI.

Military personnel and physically active civilians are particularly vulnerable to ankle sprains and subsequent chronic ankle instability (CAI). CAI is a complex neuromusculoskeletal condition characterized by recurring ankle sprains, episodes of instability, ongoing pain, and functional disability that results in activity limitations and participation or duty restrictions. Despite mitigation efforts, ankle sprains continue to occur frequently and commonly progress to CAI. CAI is associated with deficiencies in neurocognitive function (i.e., the ability to think, reason, and react) and increased instability during dual-tasks. These neurocognitive deficiencies identify a novel impairment that should be addressed during CAI rehabilitation. However, current evidence-based protocols for CAI lack dual-task exercises that incorporate visual and cognitive components simultaneously. Thus, training neurocognitive function simultaneously with traditional CAI impairments, may improve outcomes and mitigate episodes of giving way, recurrent ankle sprains, and subsequent lower extremity Musculoskeletal Injuries (MSKIs), culminating in improved Service member and civilian outcomes, continued involvement in physical activity, and active duty status retention. Hence, the overall objective of the Neurocognitive Ankle Training for Instability to Optimize Neuromusculoskeletal outcomes (NATION) study, is to examine the effectiveness of a novel ankle rehabilitation protocol on improving clinical and health outcomes in physically active individuals with CAI. The overall objective will be achieved by the following Specific Aims: Specific Aim 1: Determine the effectiveness of NATION on improving clinical outcomes compared to an evidence-based rehabilitation intervention and control arm in physically active individuals with CAI at 6-weeks and 6-months post-enrollment. Hypothesis 1: Our novel CAI rehabilitation protocol will result in improved range of motion, postural control, strength, somatosensation, lower extremity function, and motor-cognition as compared to an evidence-based protocol and control arm. Specific Aim 2: Determine the effectiveness of NATION on improving health outcomes compared to an evidence-based rehabilitation intervention and control arm in physically active individuals with CAI at 6-weeks and 6-months post-enrollment. Hypothesis 2: Our novel CAI rehabilitation protocol will result in improved self-reported function and quality of life, less injury-related fear and pain, fewer episodes of the ankle giving way, and lower MSKI rates compared to an evidence-based protocol and control arm. Specific Aim 3: Determine the effectiveness of NATION on improving Service member outcomes compared to an evidence-based rehabilitation intervention and control arm in Service members with CAI at 6-weeks and 6-months post-enrollment. Hypothesis 3: Our novel CAI rehabilitation protocol will result in improved confidence to deploy compared to an evidence-based pr trial.show_full_description

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).