Balance Training With tDCS for CAI

Not Applicable

Completed

Brief Summary: The purpose of this research study is to examine the efficacy of non-invasive brain stimulation in addition to balance exercise for chronic ankle instability (CAI), a condition that develops following an initial ankle sprain, usually because of loose or unstable ankle joints.

Recruitment & Eligibility

Inclusion Criteria

Subjects should be neurologically sound
Subjects should have abilities to maintain a single-leg stance at least for 10 seconds.
A history of ankle sprain
A history of ankle joint giving ways
Current feelings of ankle joint instability

Exclusion Criteria

Individuals with a clinically defined neurological disorder, with an increased risk of seizure for any reason, with a history of treatment with Transcranial Magnetic Stimulation (TMS), deep brain stimulation for any disorder will be excluded.
Patients with cardiac pacemakers, implanted medication pumps, intracardiac lines, or acute, unstable cardiac disease, with intracranial implants (e.g. aneurysm clips, shunts, stimulators, cochlear implants, or electrodes) or any other metal object within or near the head, excluding the mouth, that cannot be safely removed will be excluded.
A history of balance or vestibular disorder
A history of previous surgeries to the musculoskeletal structures in either limb of the lower extremity
A history of a fracture in either limb of the lower extremity requiring realignment
A history of acute injuries to the lower extremity joints in the previous 3 months, which impacted joint integrity and function (i.e., sprains, fractures) resulting in at least 1 interrupted day of desired physical activity
A history of herniated disc
Poorly controlled headache
Hypersensitivity to electrical or magnetic stimulation
Adults unable to consent
Individuals who are not yet adults (infants, children, teenagers)
Pregnant women
Prisoner

Arm && Interventions

Group	Intervention	Description
Anodal tDCS and Balance Training (BT) Group	Anodal tDCS	Participants will undergo 4 weeks of BT under anodal tDCS treatment.
Sham tDCS and BT Group	Sham tDCS	Participants will undergo 4 weeks of BT under sham tDCS.

Primary Outcome Measures

Name	Time	Method
Static Postural Balance	Week 4	Center of Pressure (COP) velocity (cm/s)
Active Motor Threshold (AMT)	4 weeks	The active motor threshold (AMT) was measured by transcranial magnetic stimulation (TMS) using a computation program, Parameter Estimation by Sequential Testing (PEST). AMT was defined as the minimum TMS intensity required to elicit an adequate motor-evoked potential (MEP) in the soleus muscle. A lower AMT reflects greater corticospinal excitability. The unit of measure is Percentage of Maximum Stimulus Output (MSO)

Secondary Outcome Measures

Name	Time	Method
Corticospinal Excitability as Evaluated by the Peak-to-peak Amplitude of Motor Evoked Potential (MEP)	4 weeks	The soleus active muscle response, due to transcranial magnetic stimulation (TMS) pulses over the motor cortex, will be used for quantifying the motor evoked potential.
Dynamic Postural Balance as Measured by the Time to Complete the Lateral Hop	4 weeks	The completion time (seconds) for the lateral hop will be measured. Each trial consists of 10 lateral hops. The average completion time of 3 trials will be reported. The completion time will be recorded using a stopwatch in seconds.
Self-reported Functional Scores	4 weeks	The percentage score of the Foot and Ankle Ability Measure (FAAM). The total percentage score ranges from 0-100. The higher score indicates a better ankle function.
Spinal Reflex Excitability	4 weeks	The maximal peak-to-peak amplitude ratios of the Hoffman reflex (H-reflex) and the motor response (M-wave) of the soleus muscle were calculated by normalizing the maximal H-reflex amplitude to the maximal M-wave amplitude (Hmax/Mmax ratio). A higher Hmax/Mmax indicates a greater spinal reflex excitability.
Dynamic Postural Control as Measured by the Reach Distance	4 weeks	The anterior reach distance (cm) was measured by the Star Excursion Balance Test (SEBT).