Acute Blood Flow Restriction Impact on Muscle Activation in Lower Extremities and Its Significance for Clinical Treatment

Background: Acute blood flow restriction (BFR) training has been recognized for its potential benefits in increasing muscle strength and hypertrophy. However, the specific effects of acute BFR on muscle activation in the lower leg during exercise, such as deep squats, under different weight-bearing conditions have yet to be explored. This study aimed to investigate the effect of acute BFR on muscle activation in the lower leg during the deep squat and discuss its importance in clinical nursing. Methods: Twenty-five female participants performed deep squats under low-intensity (LI), LI-BFR, high-intensity (HI), or HI-BFR. While the LI groups used bodyweight squats, the HI groups used 75% of one repetition maximum. A pressurized band was tied to the upper third of the thigh with the restrictive pressure determined by the thigh dimension. Electromyography signals of the biceps femoris, semitendinosus (SEM), gluteus maximus (GM), lateralis, vastus medialis (VMO), and rectus femoris (RF) were collected and the standardized values of the root mean square (RMS) of each muscle were calculated. Results: The RMS values were lower in the LI-BFR than in the LI group and changes were significant for the GM, VMO, RF ( P < 0.05), SEM, and vastus lateralis ( P < 0.01). The RMS values were also lower in the HI-BFR than in the HI group and changes were significant for the lateral femoral ( P < 0.05), RF ( P < 0.05), and medial femoral muscles ( P < 0.01). The RMS standard values of the lower extremity muscles were higher in the HI than in the LI groups ( P < 0.01). Following the increase in intensity, the elevation rate of the RMS values in the lower extremity muscles was similar under both pressurized and nonpressurized conditions ( P > 0.05). Conclusions: The results of this study highlight that increasing the load effectively enhances muscle activation in the lower extremities during deep squats, but no positive impact of acute BFR on muscle activation was observed. Under BFR conditions, there was no further increase in muscle activation beyond what was achieved with increased load alone. This clinical nursing intervention method still requires further exploration, particularly in enhancing muscle strength and function in individuals undergoing rehabilitation or experiencing muscle atrophy. At least during the training process, no observed increase in muscle activation was observed. Further research and the development of evidence-based guidelines are necessary to explore the full potential of acute BFR in clinical nursing practice.