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- Title
Blood flow restriction increases necessary muscle excitation of the elbow flexors during a single high-load contraction.
- Authors
Olmos, Alex A.; Montgomery Jr., Tony R.; Sears, Kylie N.; Dinyer, Taylor K.; Hammer, Shane M.; Bergstrom, Haley C.; Hill, Ethan C.; Succi, Pasquale J.; Lawson, John; Trevino, Michael A.
- Abstract
Purpose: To investigate the effects of blood flow restriction (BFR) on electromyographic amplitude (EMGRMS)–force relationships of the biceps brachii (BB) during a single high-load muscle action. Methods: Twelve recreationally active males and eleven recreationally active females performed maximal voluntary contractions (MVCs), followed by an isometric trapezoidal muscle action of the elbow flexors at 70% MVC. Surface EMG was recorded from the BB during BFR and control (CON) visits. For BFR, cuff pressure was 60% of the pressure required to completely occlude blood at rest. Individual b (slope) and a terms (gain) were calculated from the log-transformed EMGRMS–force relationships during the linearly increasing and decreasing segments of the trapezoid. EMGRMS during the steady force segment was normalized to MVC EMGRMS. Results: For BFR, the b terms were greater during the linearly increasing segment than the linearly decreasing segment (p < 0.001), and compared to the linearly increasing segment for CON (p < 0.001). The a terms for BFR were greater during the linearly decreasing than linearly increasing segment (p = 0.028). Steady force N-EMGRMS was greater for BFR than CON collapsed across sex (p = 0.041). Conclusion: BFR likely elicited additional recruitment of higher threshold motor units during the linearly increasing- and steady force-segment. The differences between activation and deactivation strategies were only observed with BFR, such as the b terms decreased and the a terms increased for the linearly decreasing segment in comparison to the increasing segment. However, EMGRMS–force relationships during the linearly increasing- and decreasing-segments were not different between sexes during BFR and CON.
- Subjects
BLOOD flow; MOTOR unit; FLEXOR muscles; BICEPS brachii; ELBOW; TRAPEZOIDS
- Publication
European Journal of Applied Physiology, 2024, Vol 124, Issue 6, p1807
- ISSN
1439-6319
- Publication type
Article
- DOI
10.1007/s00421-023-05405-y