Effect of Neuromuscular Electrical Stimulation Combined With Blood Flow Restriction on Muscular and Cardiovascular Function

NCT ID: NCT03662555

Last Updated: 2018-09-12

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 50 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-09-26
• Study Completion Date: 2019-09-30

Brief Summary

Neuromuscular electrical stimulation (NMES) has recently been combined with blood flow restriction (BFR) in controlled trials and has shown increased muscular strength and size compared with NMES and BFR on their own. However, none have used BFR pressures previously recommended. The first study of my Ph.D. found 40% and 80% BFR pressures to induce acute fatigue and muscle swelling. However, 80% caused higher ratings of pain and perceived exertion. The present study will determine whether NMES combined with either 40% or 80% BFR causes greater structural muscular adaptations and is perceptually easier after 6 weeks of training.

Detailed Description

Laboratory testing will take place on 28 separate occasions, 2 familiarisation, 8 testing and 18 intervention sessions. The first session (FAM 1) will serve as a familiarisation trial to the NMES protocol, BFR stimulus and strength testing. It will be conducted 10-14 days prior to the intervention period. The second session (FAM 2) will serve as a second familiarisation trial to the NMES protocol, BFR stimulus and strength testing. This session will take place 7 days prior to the beginning of the intervention period and will serve as a standardised control period prior to the main testing. The third session (PRE) will take place 1 day prior the start of the intervention period and all future sessions will consist of strength, muscle and cardiovascular function outcome measures. The fourth session (MID) will take place the morning following 3 weeks of training. The fifth session (POST1) will take place 48 hours following 6 weeks of training. There will also be post testing sessions after three days (POST2), one week (POST3) and two weeks post intervention (POST4) to assess detraining. Participants will be provided with protein supplementation after every training session. All strength, muscle and hemodynamic measurements will be conducted at St Marys University by Paul Head. Supplements should be avoided for 72 hours prior to experimental measures and throughout the intervention period. All repeated measures will be performed at a similar time of day (± 1 h).

Conditions

Muscle Weakness; Muscle Atrophy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

NMES and BFR (80%)

Group 1, participants will undergo NMES and BFR (80% pressure) applied to the quadriceps for 25 min.

Group Type: EXPERIMENTAL

Neuromuscular electrical stimulation

Intervention Type: DEVICE

Neuromuscular electrical simulation (NMES) Two self-adhesive electrodes (2 mm thick) will be placed over the rectus femoris, vastus medialis and vastus lateralis muscles. The electrodes will be placed on the motor points of each muscle. The stimulator discharges biphasic rectangular pulses. The stimulation frequency and duty cycle will be 50 Hz and 5 s of stimulation followed by a 5 s pause for each rep. The intensity of electrical flow will be at each subject's maximum that they can tolerate. The stimulation will be for 5 x 5 min sets with 1 min rest between sets.

Blood flow restriction

A handheld Doppler probe (Hi-Dop) will detect their auscultatory and visual pulse using the doppler's screen. The cuff will be inflated initially up to their systolic blood pressure and then incrementally by 10 mmHg until no auscultatory or visual pulse is detected. A percentage of 40% or 80% of each subject's LOP will then be used during the BFR conditions.

NMES and BFR (40%)

Group 2, participants will undergo NMES and BFR (40% pressure) applied to the quadriceps for 25 min.

Group Type: EXPERIMENTAL

Neuromuscular electrical stimulation

Intervention Type: DEVICE

Neuromuscular electrical simulation (NMES) Two self-adhesive electrodes (2 mm thick) will be placed over the rectus femoris, vastus medialis and vastus lateralis muscles. The electrodes will be placed on the motor points of each muscle. The stimulator discharges biphasic rectangular pulses. The stimulation frequency and duty cycle will be 50 Hz and 5 s of stimulation followed by a 5 s pause for each rep. The intensity of electrical flow will be at each subject's maximum that they can tolerate. The stimulation will be for 5 x 5 min sets with 1 min rest between sets.

Blood flow restriction

A handheld Doppler probe (Hi-Dop) will detect their auscultatory and visual pulse using the doppler's screen. The cuff will be inflated initially up to their systolic blood pressure and then incrementally by 10 mmHg until no auscultatory or visual pulse is detected. A percentage of 40% or 80% of each subject's LOP will then be used during the BFR conditions.

NMES alone

Group 3, participants will undergo NMES applied to the quadriceps for 25 min.

Group Type: ACTIVE_COMPARATOR

Neuromuscular electrical stimulation

Intervention Type: DEVICE

Neuromuscular electrical simulation (NMES) Two self-adhesive electrodes (2 mm thick) will be placed over the rectus femoris, vastus medialis and vastus lateralis muscles. The electrodes will be placed on the motor points of each muscle. The stimulator discharges biphasic rectangular pulses. The stimulation frequency and duty cycle will be 50 Hz and 5 s of stimulation followed by a 5 s pause for each rep. The intensity of electrical flow will be at each subject's maximum that they can tolerate. The stimulation will be for 5 x 5 min sets with 1 min rest between sets.

Blood flow restriction

A handheld Doppler probe (Hi-Dop) will detect their auscultatory and visual pulse using the doppler's screen. The cuff will be inflated initially up to their systolic blood pressure and then incrementally by 10 mmHg until no auscultatory or visual pulse is detected. A percentage of 40% or 80% of each subject's LOP will then be used during the BFR conditions.

Interventions

Neuromuscular electrical stimulation

Neuromuscular electrical simulation (NMES) Two self-adhesive electrodes (2 mm thick) will be placed over the rectus femoris, vastus medialis and vastus lateralis muscles. The electrodes will be placed on the motor points of each muscle. The stimulator discharges biphasic rectangular pulses. The stimulation frequency and duty cycle will be 50 Hz and 5 s of stimulation followed by a 5 s pause for each rep. The intensity of electrical flow will be at each subject's maximum that they can tolerate. The stimulation will be for 5 x 5 min sets with 1 min rest between sets.

Blood flow restriction

A handheld Doppler probe (Hi-Dop) will detect their auscultatory and visual pulse using the doppler's screen. The cuff will be inflated initially up to their systolic blood pressure and then incrementally by 10 mmHg until no auscultatory or visual pulse is detected. A percentage of 40% or 80% of each subject's LOP will then be used during the BFR conditions.

Intervention Type: DEVICE

Other Intervention Names

Blood flow restriction

Eligibility Criteria

Inclusion Criteria

• Healthy adults aged between 18 and 45 years old

Exclusion Criteria

• History of lower extremity surgery, traumatic injuries to the ankle, knee, hip, pelvis and lower back
• Current musculoskeletal condition
• High blood pressure
• Cardiovascular pathology

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

St. Mary's University, Twickenham

OTHER

Sponsor Role: lead

Responsible Party

Paul Head

PhD candidate

Responsibility Role: PRINCIPAL_INVESTIGATOR

Other Identifiers

Stmarys

Identifier Type: -

Identifier Source: org_study_id