Optimizing Clinical Outcomes for Patients with Chronic Ankle Instability Using Foot Intensive Rehabilitation (FIRE)

Background: Ankle injuries account for the highest proportion of musculoskeletal injuries among conventional and special warfare combatants. In the civilian population, 40% of lateral ankle sprain patients will go on to develop chronic ankle instability (CAI). If the same frequency is true in military settings, then up to 36,800 service members develop CAI on an annual basis. Our research team has identified several key somatosensory, motor, and mobility impairments of the foot in patients with CAI. Although foot function is compromised in patients with CAI, these impairments are not addressed by current standard of care (SOC) rehabilitation protocols which may be a limiting factor to their effectiveness. Therefore, the purpose of this randomized controlled trial is to demonstrate that a novel Foot Intensive Rehabilitation (FIRE) protocol will create more effective clinical outcomes compared to SOC rehabilitation for patients with CAI. Relevance to Topic Area: The proposed study is related to the FY19 PRORP Clinical Trial Award Focus Area of Retention on Duty Strategies and will address rehabilitation strategies that can facilitate retention on duty for common combat-related musculoskeletal injuries. Hypothesis/Objective(s): The overall objective of this study is to confirm that a 6-week FIRE intervention produces more effective clinical outcomes compared to the SOC in military and civilian patients with CAI. Our central hypothesis is that FIRE will be more effective at reducing recurrent ankle sprains, the frequency of ankle giving way episodes, and symptom severity and improving sensorimotor function and health-related quality of life compared to the SOC. Specific Aims: We expect this project will directly lead to advanced rehabilitation protocols applicable to both military and civilian populations through the execution of following the specific aims: Specific Aim 1: Determine the effect of FIRE on recurrent ankle sprain rates, frequency of ankle giving way episodes, and perceived CAI symptom severity. Specific Aim 2: Determine the effect of FIRE on sensorimotor function in CAI patients. Specific Aim 3: Determine the effect of FIRE on health-related quality of life in CAI patients. Study Design: Specific Aims 1-3 will be addressed using a multisite, single-blinded, randomized controlled trial design with data collected at the University of Kentucky, University of Virginia, and Naval Hospital Camp Pendleton. Between all sites, a total of 150 CAI patients (50 per site) will be randomly assigned to one of two groups (FIRE or SOC). Patients in both groups will complete a 6-week intervention composed of supervised exercises. Patients assigned to SOC will complete exercises focused on ankle strengthening, balance training and range of motion. Patients assigned to FIRE will complete the SOC exercises plus exercises focused on intrinsic foot muscle activation, foot stability, and plantar cutaneous stimulation. All participants will complete a series of testing at baseline, post-intervention, 6-month follow-up, 12-month follow-up, and 24-month followup to assess recurrent injury, sensorimotor function (balance, strength) and health-related quality of life. Clinical Impact: This study will establish FIRE as a more effective strategy to reduce recurrent injury and optimize sensorimotor and health-related quality of life outcomes. Therefore, we anticipate the participants enrolled in this study will experience a number of positive health outcomes directly attributed to participation in this clinical trial. This study will also generate knowledge products specifically in the form of a technical report, evidence-based treatment protocol, and clinician training and patient education materials which will be provided through a Knowledge Transfer Agreement with the Physical Therapy Specialty Leaders of the Navy, Army, and Air Force for distribution to clinicians throughout the military health system. Military Relevance: The repetitive injuries and diminished physical capabilities experienced by patients with CAI poses a substantial threat to operational readiness and the long term health of service members. This study supports the vision of the FY19 PRMRP to improve the health and well-being of military service members, veterans, and beneficiaries by validating FIRE as a new clinical strategy to optimize health outcomes for military and civilian patients with CAI.