School of Kinesiology & Physical Therapy, Division of Kinesiology, University of Central Florida, Orlando, USA.
Florida Space Institute, Partnership I, Research Parkway, University of Central Florida, Orlando, USA.
J Musculoskelet Neuronal Interact. 2023 Jun 1;23(2):165-174.
The purpose of this investigation was to examine the acute effects of low-load blood flow restriction (LLBFR) and low-load (LL) resistance exercise on muscle excitation, neuromuscular efficiency, and average torque.
Eleven men (age±SD=22±3yrs) randomly performed LLBFR and LL that consisted of 30 unilateral leg extensions at 30% of one-repetition maximum while surface electromyography (sEMG) and torque were simultaneously assessed. Polynomial regression analyses and slope comparisons were performed to examine patterns of responses and rates of change.
sEMG amplitude increased for LLBFR (9 of 11) and LL (8 of 11) and between composite responses (R=0.939-0.981). For LLBFR, sEMG amplitude increased to a greater extent for 5 of the 11 individual and for the composite responses. Similarly, neuromuscular efficiency decreased for LLBFR (8 of 11) and LL (5 of 11) as well as the composite responses r=0.902-0.929, but the decrease was larger for LLBFR than LL for the individual (4 of 11) responses. For average submaximal concentric torque, there were individual increases, decreases, and no changes for the composite responses (R=0.198-0.325).
LLBFR elicited greater fatigue-induced increases in muscle excitation and decreases in neuromuscular efficiency than LL, but neither LLBFR nor LL affected average submaximal concentric torque.
本研究旨在探讨低负荷血流限制（LLBFR）和低负荷（LL）抗阻运动对肌肉兴奋、神经肌肉效率和平均力矩的急性影响。
11 名男性（年龄±标准差=22±3 岁）随机进行 30 次单侧腿伸展运动，负荷为 1 次最大重复值的 30%，同时评估表面肌电图（sEMG）和力矩。采用多项式回归分析和斜率比较来观察反应模式和变化率。
sEMG 振幅在 LLBFR（11 人中的 9 人）和 LL（11 人中的 8 人）以及复合反应中增加（R=0.939-0.981）。对于 LLBFR，11 个人中有 5 个人和复合反应的 sEMG 振幅增加幅度更大。同样，神经肌肉效率在 LLBFR（11 人中的 8 人）和 LL（11 人中的 5 人）以及复合反应中下降（r=0.902-0.929），但 LLBFR 比 LL 对个体（11 人中的 4 人）反应的下降幅度更大。对于平均亚最大向心力矩，复合反应中有个体增加、减少和不变（R=0.198-0.325）。
与 LL 相比，LLBFR 引起的肌肉兴奋增加和神经肌肉效率降低更为明显，但 LLBFR 和 LL 均未影响平均亚最大向心力矩。
