Addressing Neuromuscular Deficits for Improved Outcomes in Ankle Rehabilitation

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".

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