Electromyographic Response to Blood Flow Restriction Exercise in Healthy Adults
Conditions
Brief summary
This pilot randomized contralateral within-participant study evaluated the immediate neuromuscular response to low-load knee extension exercise performed with and without blood flow restriction in healthy young adults. Participants were randomized in a 1:1 ratio to one of two limb-allocation groups: blood flow restriction applied to the dominant limb or blood flow restriction applied to the non-dominant limb. In each participant, the contralateral limb completed the same exercise protocol without blood flow restriction. Therefore, all participants were assessed under both experimental conditions. Both limb-specific conditions were completed during the same experimental session. The order of the blood flow restriction and non-blood flow restriction conditions was randomized for each participant, with a 10-minute rest period between conditions. Blood flow restriction was applied using a pneumatic cuff positioned on the proximal thigh. Cuff pressure was individualized and set at 80% of the arterial occlusion pressure measured for the corresponding limb. Participants completed the same standardized low-load knee extension protocol under both conditions. Surface electromyography was used to record vastus lateralis activity from each assessed limb during the exercise protocol. Muscle activity was primarily evaluated using root mean square amplitude normalized to the pre-exercise maximal voluntary isometric contraction recorded from the corresponding limb. Root mean square amplitude during maximal voluntary isometric contraction trials was also recorded before and immediately after each condition. The study aimed to compare the electromyographic response between the blood flow restriction and non-blood flow restriction conditions and to determine whether this response differed according to whether blood flow restriction was applied to the dominant or non-dominant limb.
Interventions
PROCEDUREBilateral low-load knee extension exercise protocol
Each participant completed the low-load knee extension exercise protocol separately with both lower limbs. Under each condition, the protocol comprised 75 repetitions distributed across four sets of 30, 15, 15, and 15 repetitions, with 30 seconds of rest between sets. One limb performed the protocol with blood flow restriction and the contralateral limb performed it without blood flow restriction. Condition order was randomized, and a 10-minute rest period was provided between the two limb-specific conditions. Vastus lateralis surface electromyography was recorded continuously during each protocol.
DEVICEPneumatic blood flow restriction cuff
A pneumatic cuff was placed on the proximal thigh of the limb randomized to the blood flow restriction condition and inflated to 80% of the individualized arterial occlusion pressure during the low-load knee extension protocol. The cuff was not applied to the contralateral limb, which completed the same protocol under the non-blood flow restriction condition. The cuff was fully deflated and removed after completion of the blood flow restriction condition.
Sponsors
Universidad de Extremadura
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Age between 18 and 65 years. * Healthy adults. * Absence of active pain or musculoskeletal injury in the lower limbs at the time of assessment. * Ability to understand the study procedures. * Voluntary agreement to participate and provision of written informed consent.
Exclusion criteria
* History of neuromuscular disease. * History of cardiovascular disease. * History of peripheral vascular disease. * History of thromboembolic events. * Uncontrolled hypertension. * Skin lesions or skin conditions preventing placement of the blood flow restriction cuff or surface electromyography electrodes. * Recent lower limb surgery. * Pregnancy. * Any other contraindication to blood flow restriction exercise.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Vastus Lateralis Electromyographic Amplitude Normalized to Maximal Voluntary Isometric Contraction | During the exercise protocol, within a single experimental session. | Surface electromyographic activity of the vastus lateralis was assessed during the low-load knee extension exercise protocol. The root mean square amplitude was normalized to the maximal voluntary isometric contraction recorded before exercise and expressed as percentage of maximal voluntary isometric contraction (%MVIC). Measurements were extracted at predefined time points across the four exercise sets in both experimental conditions. |
Countries
Spain
Outcome results
None listed