Effects of tDCS on Anaerobic Power of Lower Limb Muscles

Study Overview
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Brief Summary
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Anaerobic power and capacity are essential in many human activities, especially during sports practice that demand a high strength and power of the limbs. Transcranial direct current stimulation is a noninvasive technique that can modulate motor brain areas involved in motor functions and has the potential to optimize muscle capacity. However, their effects on mechanical power are lacking. This study aims to investigate the effects of transcranial direct current stimulation (tDCS) on mechanical power in healthy subjects.

Detailed Description
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In this study, a randomized, crossover, double-blind, placebo-controlled experimental design will be used. The 50 participants will be randomized into two groups: (1) Anodal tDCS(real) and (2) Sham tDCS. A single session of anodal and sham tDCS will be performed on each task (pre and post-jump test). All evaluations will be performed by a single researcher who, like the participants, will not know which stimulation group will be participating. Subjects who agree to the conditions and sign the consent form may participate in the study. Participants who meet the eligibility criteria will be included in the study.

Official Title
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Effects of tDCS on Mechanical Power of the Leg Extensor Muscles of Healthy Subjects

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Device: Transcranial direct current stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy subjects with no complaints of pain or any kind of discomfort in the musculoskeletal system Exclusion Criteria: Musculoskeletal or neurological disorder Under medication Previous treatment with tDCS

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: tDCS (anodal)<br>tDCS: 20 minutes, 2mA, over the motor cortex representation of lower limbs. | Device: Transcranial direct current stimulation<br>* Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation (NIBS) technique that has been investigated for the management of various health conditions. However, its ergogenic effect still has controversial results.<br>|
| Sham Comparator: tDCS (sham)<br>tDCS: 20 minutes (but 30s ON), 2mA, over the motor cortex representation of lower limbs. | Device: Transcranial direct current stimulation<br>* Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation (NIBS) technique that has been investigated for the management of various health conditions. However, its ergogenic effect still has controversial results.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean anaerobic power | Mean anaerobic power will be evaluated by assessing the ground reaction forces (GRF) and the number of jumps in each test by means of the kinetic analysis of the 60-second vertical jump test (Bosco's Test). | Pre and Post-test (immediately after tDCS) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak anaerobic power | Peak anaerobic power will be evaluated by assessing the ground reaction forces (GRF) and the number of jumps in each test by means of the kinetic analysis of the 60-second vertical jump test (Bosco's Test). | Pre and Post-test (immediately after tDCS) | 
| Fatigue index | Fatigue index will be evaluated by assessing the ground reaction forces (GRF) and the number of jumps in each test by means of the kinetic analysis of the 60-second vertical jump test (Bosco's Test). The fatigue index corresponds to the power reduction rate expressed as a percentage and reveals the degree of reduction in the ability to produce strength and maintain exercise. | Pre and Post-test (immediately after tDCS) | 
| Rating of perceived exertion | The subjective feeling of effort will be assessed by the Borg scale for perceived effort. This is a 15-point numerical scale that ranges from 6 to 20, where 6 means no exertion at all and 20 means maximal exertion. | Post-test (immediately after tDCS) |