Addressing Neuromuscular Deficits for Improved Outcomes in Ankle Rehabilitation

The purpose of this project is to compare a novel sensorimotor ankle rehabilitation training (SMART) protocol for Lateral ankle sprains (LASs) against a standard of care (SOC) protocol to determine if it is more successful at producing successful one-year outcomes and lower rates of re-injury and improved health. This will address the identified needs for evidence-support and reintegration strategies to improve understanding of the management of patient rehabilitation strategies throughout the rehabilitation process following neuromusculoskeletal injury. The project will validate an innovative rehabilitation approach while providing metrics of success using a variety of clinical and innovative markers.

Background: Ankle injuries are the most common musculoskeletal injuries in the military and civilian populations, creating a substantial time loss that equates to a $5.5 billion annual financial burden. Up to 70% who sustain a lateral ankle sprain (LAS) will develop chronic ankle instability (CAI), with persistent functional disability and injury recurrence. Over 70% of CAI cases will develop early onset post-traumatic ankle joint osteoarthritis (PTOA), with consequent deteriorations in physical activity and health-related quality of life. Given the rate of injuries and discharge rates in the military, the need to deliver improved care to disrupt the path to PTOA is warranted. Our preliminary data demonstrates deficits in central nervous system (CNS) function in patients with CAI, which supports the inclusion of sensorimotor tasks into rehabilitation as an effective means to improve lingering dysfunction and decrease disability in patients with CAI. However, to our knowledge, no investigation has employed these sensorimotor techniques in rehabilitation for acute LAS patients. Therefore, the purpose of this study is to demonstrate the effectiveness of a sensorimotor ankle rehabilitation training (SMART) protocol compared to a standard of care (SOC) protocol at improving clinical and novel outcomes, which will associate with lower rates of LAS re-injury and development of CAI during a 12-month follow-up period. The proposed project is aligned with multiple FY17-18 JPC-8/CRMRP NMSIRRA Focus Areas (i.e. Limited understanding of the management of patient rehabilitation strategies throughout the rehabilitation process following neuromusculoskeletal injury) and Identified Areas of Emphasis (i.e. Develop and evaluate innovative rehabilitation techniques for Service members with neuromusculoskeletal injuries).

Hypotheses: Hypothesis 1.1: Compared to the SOC, LAS patients participating in the SMART program will have improved clinical outcomes at the time of return to full activity. Hypothesis 1.2: Compared to the SOC, LAS patients participating in the SMART program will have improved clinical outcomes and lower LAS re-injury rates at the 6-month follow-up. Hypothesis 1.3: Compared to the SOC, LAS patients participating in the SMART program will have improved clinical outcomes, lower LAS re-injury rates, and less ankle joint cartilage turnover at the 12-month follow-up. Hypothesis 2.1: Compared to the SOC, LAS patients participating in the SMART program will have improved central nervous system function at the time of return to activity, and at the 6-month and 12-month follow-ups. Hypothesis 3.1: Improved mechanistic measures in these innovative outcomes will help explain the success from SMART on the clinical outcomes and ankle joint integrity at the 12-month follow-up.

Specific Aims and Objectives: Our primary purpose is to compare a novel SMART protocol against a SOC protocol to determine if it is more successful at producing successful one-year outcomes and lower rates of re-injury after acute LAS. Specific Aim #1: Determine if SMART improves clinical outcomes (patient-reported function and quality of life, LAS re-injury rates, postural control, ankle ROM) and ankle joint integrity (articular cartilage turnover) in LAS patients. Specific Aim #2: Determine if SMART improves innovative measures of CNS function (corticospinal excitability and brain white matter integrity) in LAS patients. Specific Aim #3: Delineate the association between explanatory mechanistic measures (corticospinal excitability and brain white matter integrity) and the hypothesized improvements in clinical and ankle joint integrity in LAS patients receiving SMART.

Research Strategy: Using a prospective cohort study design, we will compare clinical and CNS outcome measures between cohorts that do or do not develop CAI during the 12 months following an acute LAS from University of Kentucky, University of North Carolina, and Fort Bliss/William Beaumont Army Medical Center. Patients initiating rehabilitation for acute LAS will be randomly assigned to either a SOC or a SMART protocol. Testing will be performed when patients are cleared to return to full duty/activity, and 6 and 12 months after return to duty/activity to determine success in clinical and innovative outcomes.

Military Benefit and Impact: The proposed research study will directly translate to improved clinical outcomes following LAS and prevention of CAI and ankle PTOA. Our work will confirm the need for more comprehensive physical therapy for LAS that addresses sensorimotor deficits that persist commonly after completion of a SOC treatment, bringing a significant clinical impact. This will alleviate financial burdens and time-loss from the common injuries sustained to the ankle, translating into more LAS patients experiencing optimal short-term re-integration and long-term sustained performance, achieving the ultimate goal of "Total Readiness".

Eligibility Criteria:
Inclusion Criteria:

* initiating rehabilitation for a first time acute grade I, II, or III LAS
* have sustained within 72 hours of study enrollment
* diagnosed by a physician, medic, athletic trainer, physical therapist, or other providing medical coverage in operational environments as having sustained a LAS

Exclusion Criteria:

* personal or familial history of epilepsy or seizures
* history of migraine headaches
* ocular foreign body, increased intracranial pressure, open head injury or significant closed head injury
* cochlear implants
* implanted brain stimulators, aneurysm clips or other metal in the head (except mouth)
* implanted medication pumps, pacemakers or intracardiac lines
* current medication with tricyclic anti-depressants, neuroleptic agents or other drugs that lower seizure threshold
* history of diagnosed major psychiatric disorder
* history of illicit drug use
* current alcohol abuse or currently withdrawing from alcohol abuse
* history of heart disease