Neuromuscular Adaptations After Training in the Muscle Belly of Triceps Surae

Study Overview
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Brief Summary
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This study aims to evaluate on an acute session of the central and peripheral contributions of electrical stimulation on the muscle belly of the triceps surae, electrical stimulation of the tibial nerve and voluntary exercise of the triceps surae muscle, and identify responders individuals and non-responders to stimulation of the tibial nerve. Another objective of the study is to compare the effects of conventional electrical stimulation applied to the sciatic triceps muscle, tibial nerve stimulation and voluntary exercise after eight weeks of training in healthy individuals.

Detailed Description
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A controlled randomized controlled trial will be carried out by university students, divided equally into four groups: control group (GC), long responding pulse group (PLR), non-responder long pulse group (PLNR) and pulsed current group (CP) after the acute fase of the protocol. Muscular architecture (muscle thickness, pennation angle and fascicle length) of the muscles composing the sural triceps, H-reflex and M-wave tests (central and peripheral contribution), electromyographic signals of the medial and lateral gastrocnemius muscles and sole, voluntary and evoked joint torque of the muscles composing the sural triceps and level of sensorial discomfort. The independent intervention with the neuromuscular electrical stimulation and the isometric exercises performed by the control group will be considered as an independent variable. All groups will have the dependent variables evaluated 6 times, before, during and after the intervention, which will consist of 24 sessions (8 weeks). The training with neuromuscular electrical stimulation (NMES) will be performed 3 times a week and will never be applied for two consecutive days, as well as the voluntary exercises performed by the control group.

Official Title
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Neuromuscular Adaptations After Training With Neuromuscular Electrical Stimulation Applied Over Nerve Trunk Compared With a Muscle Belly of Triceps Surae: Randomized Controlled Trial

Conditions
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Electrical Stimulation

Intervention / Treatment
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* Other: Voluntary exercise
* Other: Wide pulse responder group
* Other: Wide pulse non responder group
* Other: Pulsed current group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Classified as physically active according to the INTERNATIONAL QUESTIONNAIRE OF PHYSICAL ACTIVITY, To practice only recreational physical activity, Achieve minimum torque of 30% of the (maximal voluntary isometric contraction during conventional NMES Be at least 3 months without practicing strength training. Exclusion Criteria: Present some type of skeletal muscle dysfunction that may interfere with the tests, Present intolerance to NMES in the muscular or tibial nerve, Make use of analgesics, antidepressants, tranquillizers or other agents of central action To present cardiovascular or peripheral vascular problems, chronic diseases, neurological or muscular affections that will undermine the complete execution of the study design by the volunteer.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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Male

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: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Voluntary exercise<br>The participants will perform 36 voluntary contractions of 20% of maximal voluntary isometrical contraction, 3 times per week for 8 weeks. | Other: Voluntary exercise<br>* The participants will perform 36 maximal voluntary contractions, 3 times per week for 8 weeks.<br>|
| Experimental: Wide pulse responder group<br>The participants will perform 36 contractions with the following current parameters: pulsed current (100 Hz, pulse duration 1 ms, Ton: 6 s, Toff: 18 s), 3 times per week for 8 weeks. This group will classified in responder in the acute fase. | Other: Wide pulse responder group<br>* The participants will perform 36 contractions with the following current parameters: pulsed current (100 Hz, pulse duration 1 ms, Ton: 6 s, Toff: 18 s), 3 times per week for 8 weeks. This group will be classified in responder group in acute fase.<br>|
| Experimental: Wide pulse non responder group<br>The participants will perform 36 contractions with the following current parameters: pulsed current (100 Hz, pulse duration 1 ms, Ton: 6 s, Toff: 18 s), 3 times per week for 8 weeks. This group will classified in non responder in the acute fase. | Other: Wide pulse non responder group<br>* The participants will perform 36 contractions with the following current parameters: pulsed current (100 Hz, pulse duration 1 ms, Ton: 6 s, Toff: 18 s), 3 times per week for 8 weeks. This group will be classified in non responder group in acute fase.<br>|
| Experimental: Pulsed current group<br>The participants will perform 36 contractions with the following current parameters: pulsed current (100 Hz, pulse duration 250 μs, Ton: 6 s, Toff: 18 s), 3 times per week for 8 weeks. | Other: Pulsed current group<br>* The participants will perform 36 contractions with the following current parameters: pulsed current (100 Hz, pulse duration 250 μs, Ton: 6 s, Toff: 18 s), 3 times per week for 8 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline Central contribution (H reflex) after 15 minutes of acute session of electrical stimulation. | Central contribution will be measured before and after 15 minutes (36 contractions) of electrical stimulation in the acute session. | Baseline and after 15 minutes of electrical stimulation in the acute session. | 
| Change from Baseline Central contribution (H reflex) after 8 weeks of training with electrical stimulation. | Central contribution will be measured before and after 8 weeks of training with electrical stimulation. | Baseline and after 8 weeks of training with electrical stimulation. | 
| Change from Baseline Peripheral contribution (M wave) after 15 minutes of acute session of electrical stimulation | Peripheral contribution will be measured before and after acute session 15 minutes (36 contractions) of electrical stimulation in the acute session. | Baseline and after 15 minutes of electrical stimulation in the acute session | 
| Change from Baseline Peripheral contribution (M wave) after 8 weeks of traning with electrical atimulation | Peripheral contribution will be measured before and after 8 weeks of training with electrical stimulation. | Baseline and after 8 weeks of training with electrical stimulation | 
| Change from Baseline Voluntary torque after 8 weeks of training with electrical stimulation | Voluntary torque will be evaluated by an isokinetic dynamometer before and after an 8-week training period with electrical stimulation. | Baseline and after 8 weeks of training with electrical stimulation | 
| Change from Baseline Electromyographic signals after 8 weeks of training with electrical stimulation | Electromyographic signals will be evaluated by an electromyography before and after an 8-week training period with electrical stimulation. | Baseline and after 8 weeks of training with electrical stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline Evoked torque after 8 weeks of training with electrical stimulation | Evoked torque will be evaluated by an isokinetic dynamometer before and after an 8-week training period with electrical stimulation. | Baseline and after 8 weeks of training with electrical stimulation | 
| Change from Baseline Discomfort sensory after 8 weeks of training with electrical stimulation | Discomfort sensory will be evaluated by Visual Analogic Scale before and after an 8-week training period with electrical stimulation. The Visual Analogic Scale assess pain by rating the subjective perceived disconfort of the subject from 0 (no pain) to 10 (unbearable pain) | Baseline and after 8 weeks of training with electrical stimulation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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M wave, Electrical stimulation, H reflex, Wide pulse