Muscle swelling following blood flow‐restricted exercise does not differ between cuff widths in the proximal or distal portions of the upper leg

Abstract

The purpose was to understand how wider cuffs, covering larger portions of the limb, may affect acute muscle swelling when used during low‐load knee extension exercise with blood flow restriction. A total of 96 individuals (53 females and 43 males) completed two visits, with visit one used for measuring maximal strength and arterial occlusion pressure (AOP), and visit two to compare between a narrow (5 cm) and a wide (12 cm) cuff for acute changes in muscle thickness and echo intensity following exercise. Ultrasound measurements were completed at a proximal and distal site within both legs, with the proximal site located beneath the cuff within the leg exercising using the wide cuff. Study findings indicate that the difference in acute changes for muscle thickness [median difference (95% credible interval) of 0.009 (−0.03, 0.05) cm] and echo intensity [median difference (95% credible interval) of 0.79 (−0.28, 1.89) AU] between cuff widths did not differ between proximal and distal sites. Additionally, acute changes in muscle thickness did not differ between cuff widths, sexes or participants who had AOP measured and those who were estimated. Lastly, acute changes in echo intensity did not differ between cuff widths and those who had AOP measured and those who were estimated. However, there was evidence showing how there might be greater reductions in echo intensity for females at the distal site. The previously observed attenuation of muscle growth under the cuff is unlikely to be related to differences in the acute muscle swelling response.

Acute muscle swelling effects of a knee rehabilitation exercise performed with and without blood flow restriction

“…The current study’s results presented a temporary increase in mCSA at IMM-POST in males which may have been caused by the BFR quad sets, but this was a modest 4.0% and insufficient to be significantly greater than any other time point. These results contrast with previous studies that have identified significant changes in muscle size variables (MT and mCSA) of 10.7–12.6% from PRE to after exercise following knee extensions performed with BFR [ 10 – 12 ]. However, the exercises used included concentric, low-load (20–30%) voluntary contractions at varying inflation pressures (140 mmHg) or relative percentages [50% arterial occlusion pressure (AOC)].…”

“…These studies have presented mixed results, with Hackney et al [ 11 ] showing no significant differences compared to baseline in rectus femoris mCSA immediately after and 5-minutes after BFR knee extensions when compared to low-load non-BFR exercises. Conversely, the MT of the vastus lateralis can be elevated immediately after BFR knee extensions with a concomitant decrease in EI [ 10 ] and MT can be elevated up to 3-hours after BFR knee extensions compared to baseline [ 12 ], purportedly due to local swelling. Additionally, the perceived effort of BFR-mediated “work” has been reported to be much higher than non-BFR movements, hence why a standard protocol for BFR includes only 20–30% 1-repetition maximum load during dynamic, concentric resistance exercises [ 11 , 15 ].…”

“…If exercise modalities that maintain muscle mass after surgery can be utilized earlier in the recovery process, then perhaps the long-term deficits between a surgical limb and a non-surgical limb can be attenuated [ 19 , 20 ]. If BFR-mediated resistance exercise can stimulate muscular changes in healthy adults [ 10 , 12 ], studies should then assess the acute responses (e.g., changes in muscle size) of knee rehabilitation exercises performed with BFR, to determine if this provides a unique response. A substantial amount of the existing BFR literature has included both male and female participants, yet do not elucidate any sex-specific differences in BFR-driven muscular responses [ 19 , 21 , 22 ] and suggest future research should investigative if there are unique sex-related responses to BFR.…”

“…To date, two investigations have compared sex and reported varying outcomes. Young et al demonstrated similar trends between sex in vastus lateralis MT changes after BFR knee extensions [ 12 ] and Bell et al also noted no differences in MT between sex after BFR resistance exercise [ 10 ].…”

Acute Effects of Continuous and Intermittent Blood Flow Restriction on Movement Velocity During Bench Press Exercise Against Different Loads

“…When lifting loads at or above 60% 1RM, intramuscular pressure is high due to muscle tension, and thus blood flow during exercise is occluded (Sjøgaard et al, 1988;Golas et al, 2015). Also, blood flow during recovery in the latter four sets in all trials, may be compromised due to muscle swelling, as a result of osmotic changes and fluid shifts into the muscle (Sjøgaard et al, 1988;Ploutz-Snyder et al, 1995;Bell et al, 2020). Thus, if blood flow during exercise and recovery is reduced due to muscle tension and muscle swelling, Results are mean ± SD (90% confidence intervals).…”