Immediate Effect of Electrical Noise Stimulation on Neuromuscular Adaptation of Balance

Study Overview
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Brief Summary
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Noise stimulation had an immediate effect on improving balance control. The present study aimed to clarify the immediate neuromuscular adaptation induced by noise stimulation and find the correlation between neuromuscular adaptation and functional performance.

Detailed Description
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The mechanism behind noise stimulation is called Stochastic Resonance which improves the detectivity of sensory input with the presence of noise, making sub-sensory threshold input detectable. Noise stimulation had been proved to improve postural control, Ia afferent sensitivity, and muscle activity of the tibialis anterior. With this evidence of the effect of noise stimulation on balance enhancement, the neuromuscular adaptation induced by noise stimulation has not been researched yet. Therefore, the present study aims to clarify the immediate effect of noise on neuromuscular regulation during postural control.

Official Title
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Immediate Effect of Electrical Noise Stimulation on Neuromuscular Adaptation During Single-Leg Stance in Healthy Young

Conditions
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Balanced, Electroencephalography, Electromyography

Intervention / Treatment
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* Device: electrical noise stimulation
* Device: Sham stimulation
* Device: Foam


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age between 20 and 40 years old without ankle injury history in 1 year without musculoskeletal or neurological diseases that would affect balance performance without visual impairment (except vision correction or no visual problems) without vestibular impairment. Exclusion Criteria: subject who cannot tolerate the cutaneous electrical stimulation to induce H reflex single-leg stance (SLS) without support is shorter than 80 secs

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sham stimulation on stable surface<br>The participant will not receive stimulation and will stand on flat ground. | Device: Sham stimulation<br>* Participants will not receive stimulation.<br>|
| Experimental: Noise stimulation on stable surface<br>The participant will receive stimulation with intensity set at 90% of their sensory threshold and will stand on flat ground. | Device: electrical noise stimulation<br>* The intensity of electrical noise stimulation will be set at 90% of the sensory threshold of each participant.<br>|
| Experimental: Sham stimulation on unstable surface<br>The participant will not receive stimulation and will stand on foam. | Device: Sham stimulation<br>* Participants will not receive stimulation.<br>Device: Foam<br>* The foam will be used to make an unstable surface.<br>|
| Experimental: Noise stimulation on unstable surface<br>The participant will receive stimulation with intensity set at 90% of their sensory threshold and will stand on foam. | Device: electrical noise stimulation<br>* The intensity of electrical noise stimulation will be set at 90% of the sensory threshold of each participant.<br>Device: Foam<br>* The foam will be used to make an unstable surface.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean sway path of the center of pressure | The mean sway path in mm will represent balance performance | 40 seconds under each condition | 
| Mean sway velocity of the center of pressure | The mean sway velocity in mm/sec will represent balance performance | 40 seconds under each condition | 
| Cortical excitability | Power spectrum density of EEG will calculated for representing cortical excitability. | 40 seconds under each condition | 
| Spinal reflex excitability | H reflex amplitude will represent the excitability of peripheral control from spinal level nerve system. | 40 seconds under each condition | 
| Co-activation index | Co-activation index will be calculated by EMG activity of Tibialis Anterior and Soleus muscle to represent the muscle activity. | 40 seconds after each condition | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Center of pressure, Electroencephalography, Electromyography, H reflex, Electrical noise stimulation