Pulsed Current Versus Russian Current Effects in Healthy Young Subjects.

NCT03796117 | Completed

• 1 other identifier: 3.064.351
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Low frequency pulsed current (PC) and medium frequency alternating current (Russian current - RC, 2.5 kHz) have been largely studied due to their clinical use. However, it is not clear which current is the most efficient due to the existente literature conflicts.Therefore, the purpose of this study is to compare the neuromuscular efficiency, evoked torque, current intensity, fatigability and level of discomfort between the PC and the RC in healthy young. The current types will be tested in the same participant by the intervention sequences randomization. On the first, second, third and fourth days, the maximum voluntary isometric contraction (MVIC), the current intensity level, discomfort level, evoked torque, and clinical and neuromuscular efficiency of each current will be evaluated. Anthropometric measurements will also be assessed on the first day. In addition, the current intensity required to produce a torque level of 20% of the MVIC, the current intensity required to generate a torque of 40 Nm and the maximum intensity tolerated by the participant will be evaluated. Three contractions will be recorded in each condition, and the level of discomfort will be assessed during the evoked contractions. Evoked torque will be evaluated at the maximum tolerated intensity level using the isokinetic dynamometer. Clinical and neuromuscular efficiency will be evaluated (1) at the current intensity necessary to evoke 20% MVIC, (2) at the current intensity necessary to generate 40 Nm, and (3) at the maximum tolerated current intensity. On the fifth and sixth days, muscle fatigue induced by the diferente current types will be evaluated. Fatigue will be evaluated with sufficient current intensity to generate 20% of the MVIC. MVIC will be performed before and after the fatigue protocol, and the fatigue will be determined by the relative variation of the MVIC before and after the fatigue protocol. Fatigue will also be evaluated through the evoked torque variation between the first and the last minute of the fatigue protocol, as well as by the total work generated in each protocol. Neuromuscular efficiency will be evaluated before and immediately after the protocol through (1) the ratio between input NMES current intensity and output evoked torque, (2) total work (area under the evoked force by time curves) generated during the fatigue protocol, and (3) by the changes in muscle architecture from rest to evoked contraction at the maximal current intensity.

Conditions

Healthy Young; Electric Stimulation Therapy

Keywords

Muscle Strength; Fatigue; Neuromuscular efficiency; Discomfort level; Electric Stimulation

Outcome Measures

Primary Outcomes (22)

• Maximum voluntary isometric contraction of the knee extensors

  is an expression of the muscular strength, and will be evaluated by dynamometry.

  14 minutes

• Knee extensors evoked torque during the tests at submaximal current intensity levels

  is an expression describing the muscular strength generated by electrical stimulation, and will be assessed by dynamometry.

  During 90 seconds of electrical stimulation

• Knee extensors evoked torque during the tests at maximal current intensity levels

  is an expression describing the muscular strength generated by electrical stimulation, and will be assessed by dynamometry.

  During 90 seconds of electrical stimulation

• Knee extensors evoked torque during the fatigue protocol

  is an expression describing the muscular strength generated by electrical stimulation, and will be assessed by dynamometry.

  During 20 minutes of electrical stimulation

• Muscular architecture during the knee extensors maximum voluntary isometric contraction tests

  is an expression used to describe the muscle fibers arrangement within the muscle, and is evaluated by determining the muscle thickness, fascicle pennation angle and fascicle length, which will be assessed by ultrasonography.

  14 minutes

• Muscular architecture during knee extensors evoked torque tests at submaximal current intensity levels

  is an expression used to describe the muscle fibers arrangement within the muscle, and is evaluated by determining the muscle thickness, fascicle pennation angle and fascicle length, which will be assessed by ultrasonography.

  During 90 seconds of electrical stimulation

• Muscular architecture during knee extensors evoked torque tests at maximal current intensity levels

  is an expression used to describe the muscle fibers arrangement within the muscle, and is evaluated by determining the muscle thickness, fascicle pennation angle and fascicle length, which will be assessed by ultrasonography.

  During 90 seconds of electrical stimulation

• Muscular architecture during the fatigue protocol

  is an expression used to describe the muscle fibers arrangement within the muscle, and is evaluated by determining the muscle thickness, fascicle pennation angle and fascicle length, which will be assessed by ultrasonography.

  During 20 minutes of electrical stimulation

• Discomfort level generated by electrical stimulation during evoked torque tests at submaximal current intensity levels

  Discomfort will be measured with a Visual Analogue Scale (0-100mm), where 0 and 100 mm corresponded to no discomfort and worst perceived discomfort, respectively.

  During 90 seconds of electrical stimulation

• Discomfort level generated by electrical stimulation during evoked torque tests at maximal current intensity levels

  Discomfort will be measured with a Visual Analogue Scale (0-100mm), where 0 and 100 mm corresponded to no discomfort and worst perceived discomfort, respectively.

  During 90 seconds of electrical stimulation

• Discomfort level generated by electrical stimulation during the fatigue protocol

  Discomfort will be measured with a Visual Analogue Scale (0-100mm), where 0 and 100 mm corresponded to no discomfort and worst perceived discomfort, respectively.

  During 20 minutes of electrical stimulation

• Current intensity required to evoke knee extensors submaximal torque

  Current intensity is defined as the amount or amplitude of electrical current (in milliamperes - mA) required to achieve a specific force, and will be evaluated in the electrical stimulation device.

  During 90 seconds of electrical stimulation

• Current intensity required to evoke knee extensors maximal torque

  Current intensity is defined as the amount or amplitude of electrical current (in milliamperes - mA) required to achieve a specific force, and will be evaluated in the electrical stimulation device.

  During 90 seconds of electrical stimulation

• Neuromuscular efficiency during knee extensors submaximal evoked torque tests

  Neuromuscular efficiency of the electrical currents will be evaluated by calculating the current intensity (input parameter or input) by the evoked torque (output parameter) ratio.

  During 90 seconds of electrical stimulation

• Neuromuscular efficiency during knee extensors maximal evoked torque tests

  Neuromuscular efficiency of the electrical currents will be evaluated by calculating the current intensity (input parameter or input) by the evoked torque (output parameter) ratio.

  During 90 seconds of electrical stimulation

• Neuromuscular efficiency during the fatigue protocol

  Neuromuscular efficiency of the electrical currents will be evaluated by calculating the current intensity (input parameter or input) by the evoked torque (output parameter) ratio.

  During 20 minutes of electrical stimulation

• Clinical efficiency during knee extensors submaximal evoked torque tests

  Clinical efficiency of the two electrical currents will be evaluated by calculating the ratio between the evoked torque (output parameter) and the level of discomfort generated.

  During 90 seconds of electrical stimulation

• Clinical efficiency during knee extensors maximal evoked torque tests

  Clinical efficiency of the two electrical currents will be evaluated by calculating the ratio between the evoked torque (output parameter) and the level of discomfort generated.

  During 90 seconds of electrical stimulation

• Clinical efficiency during the fatigue protocol

  Clinical efficiency of the two electrical currents will be evaluated by calculating the ratio between the evoked torque (output parameter) and the level of discomfort generated.

  During 20 minutes of electrical stimulation

• Muscle Fatigue Index

  Characterized by the force decrease after the fatigue protocol, it will be evaluated by dynamometry.

  During 20 minutes of electrical stimulation

• Fatigue Index from Evoked Torque

  Characterized by the decrease of the evoked torque during the fatigue protocol, the fatigue index from evoked torque will be evaluated by dynamometry, and obtained by the analysis of evoked torque curves.

  During 20 minutes of electrical stimulation

• Total work generated during the fatigue protocol

  The torque-time integral of the evoked torque curves during the fatigue protocol will be evaluated. The sum of the torque curve integral of all evoked contractions during the fatigue protocol will be calculated to determine the total work evoked by each current during the fatigue protocol.

  During 20 minutes of electrical stimulation

Secondary Outcomes (2)

• Thickness of the subcutaneous fat layer on the motor point

  It will be evaluated during the first evaluation day.

• Level of physical activity

  8 minutes. It will be evaluated during the first evaluation day

Study Arms (2)

Experimental Group 1: healthy young

EXPERIMENTAL

Participants receive two interventions (Pulsed Current - PC, or Russian Current - RC) in a specific order, according to randomization. Evoked torque, discomfort level, current intensity, neuromuscular efficiency, clinical efficiency and fatigability level will be evaluated.

Device: Pulsed current; Device: Russian Current

Experimental Group 2: healthy young

EXPERIMENTAL

Participants receive two interventions (Pulsed Current - PC, or Russian Current - RC) in a specific order, according to randomization. Evoked torque, discomfort level, current intensity, neuromuscular efficiency, clinical efficiency and fatigability level will be evaluated.

Device: Pulsed current; Device: Russian Current

Interventions

Pulsed current DEVICE

For stage 1 of the study, which corresponds to analysis of the evoked torque, evaluation of the discomfort level, current intensity, analysis of neuromuscular efficiency and clinical efficiency, 2 configurations (PC1 and PC2) will be used. PC1, will be set at a frequency of 100 Hz, phase duration of 1000 microseconds, ON-OFF time of 5s:10s. PC2, will be set at a frequency of 100 Hz, phase duration of 200 microseconds ON-OFF time of 5s:10s. For stage 2 of the study, which corresponds to the analysis of the fatigability level, only the PC1 configuration will be used.

Experimental Group 1: healthy young; Experimental Group 2: healthy young

Russian Current DEVICE

For stage 1 of the study, which corresponds to analysis of the evoked torque, discomfort level, current intensity, neuromuscular efficiency and clinical efficiency, 2 configurations (RC1 and RC2) will be used. RC1, will be set to a frequency of 100 Hz, burst duty cycle of 20%, ON-OFF time of 5s:10s. RC2, will be set at a frequency of 100 Hz, burst duty cycle of 50%, ON-OFF time of 5s:10s. For stage 2 of the study, which corresponds to the analysis of the fatigability level, only the RC2 configuration will be used.

Experimental Group 1: healthy young; Experimental Group 2: healthy young

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Young male
• Age between 18 and 35 years
• Physically active,
• Normal knee function and range of motion
• No pain complaints
• No presence of lower limb pathology at the dominant limb.

You may not qualify if:

• Health problems (neurological, musculoskeletal impairment),
• Contraindication to maximal exercise,
• Having been treated with NMES in the last 3 months in the lower limb

Sponsors & Collaborators

• Federal University of Rio Grande do Sul: lead

Study Sites (1)

Exercise Research Laboratory, School of Physical Education, Federal University of Rio Grande do Sul

Porto Alegre, Rio Grande do Sul, 90690-200, Brazil

Location

Related Publications (1)

• Paz IA, Rigo GT, Sgarioni A, Baroni BM, Frasson VB, Vaz MA. Alternating Current Is More Fatigable Than Pulsed Current in People Who Are Healthy: A Double-Blind, Randomized Crossover Trial. Phys Ther. 2021 Jun 1;101(6):pzab056. doi: 10.1093/ptj/pzab056.

  PMID: 33561279 DERIVED

MeSH Terms

Conditions

Fatigue

Condition Hierarchy (Ancestors)

Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Marco A Vaz, PhD

  Federal University of Rio Grande do Sul

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: December 24, 2018
• First Posted: January 8, 2019
• Study Start: January 8, 2019
• Primary Completion: June 30, 2019
• Study Completion: August 30, 2019
• Last Updated: June 10, 2021

Record last verified: 2021-06

Data Sharing

• IPD Sharing: Will not share

Locations

BR (1)