Abstract：
BACKGROUND: No previous studies have implemented a standard blood flow restriction (BFR) training session in people with severe haemophilia (PwH), where this type of training has been contraindicated.
OBJECTIVE: The purpose of this study was to evaluate the tolerability, adverse events, and neuromuscular and perceptual responses to an acute session of low load (LL) knee extensions with BFR in PwH under prophylaxis.
METHODS: Eight PwH performed one LL-BFR session with 40% arterial occlusion pressure (AOP). Perceptual responses and adverse effects were assessed, together with high-density surface electromyography of vastus medialis (VM) and lateralis (VL).
RESULTS: Significant normalized root mean square differences were found within each set, but not between sets. Spatial distribution (centroid displacement (p > .05), modified entropy (VM, set two, cycles three and five, p = .032) and coefficient of variation (VM, set two, cycles four and five lower than cycle three (p = .049; p = .036)) showed changes within each set. Median frequency showed a slight increase during cycle four of set four (p = .030). Rate of perceived exertion slightly increased with each set while tolerability slightly decreased in the last set and fear of training with BFR generally decreased after the session.
CONCLUSIONS: In PwH, a LL-BFR session at 40% AOP is safe and feasible. Our results suggest that potential muscle impairments may blunt neuromuscular adaptations induced by BFR.
OBJECTIVE: The purpose of this study was to evaluate the tolerability, adverse events, and neuromuscular and perceptual responses to an acute session of low load (LL) knee extensions with BFR in PwH under prophylaxis.
METHODS: Eight PwH performed one LL-BFR session with 40% arterial occlusion pressure (AOP). Perceptual responses and adverse effects were assessed, together with high-density surface electromyography of vastus medialis (VM) and lateralis (VL).
RESULTS: Significant normalized root mean square differences were found within each set, but not between sets. Spatial distribution (centroid displacement (p > .05), modified entropy (VM, set two, cycles three and five, p = .032) and coefficient of variation (VM, set two, cycles four and five lower than cycle three (p = .049; p = .036)) showed changes within each set. Median frequency showed a slight increase during cycle four of set four (p = .030). Rate of perceived exertion slightly increased with each set while tolerability slightly decreased in the last set and fear of training with BFR generally decreased after the session.
CONCLUSIONS: In PwH, a LL-BFR session at 40% AOP is safe and feasible. Our results suggest that potential muscle impairments may blunt neuromuscular adaptations induced by BFR.
摘要：
背景：以前没有研究对重度血友病（PwH）患者实施标准血流限制（BFR）训练课程，这种类型的培训是禁忌的。
目的：本研究的目的是评估耐受性，不良事件,以及预防PwH中BFR对低负荷（LL）膝盖伸展的急性发作期的神经肌肉和知觉反应。
方法：八个PwH进行了一次LL-BFR会话，动脉闭塞压（AOP）为40％。评估了感知反应和不良反应，以及股内侧肌（VM）和外侧肌（VL）的高密度表面肌电图。
结果：在每组中发现了显着的归一化均方根差异，但不是在集合之间。空间分布(质心位移(p>.05)，修正熵(VM，设置二，第三和第五周期，p=0.032)和变异系数(VM，设置二，低于第三周期的第四周期和第五周期(p=.049;p=.036))显示每组内的变化。中值频率显示在第4组的第4周期期间略有增加(p=.030)。每组运动的感知率略有增加，而最后一组的耐受性略有下降，训练结束后对BFR训练的恐惧通常会降低。
结论：在PwH中，40%AOP的LL-BFR会话是安全可行的。我们的结果表明，潜在的肌肉损伤可能会削弱BFR诱导的神经肌肉适应。
目的：本研究的目的是评估耐受性，不良事件,以及预防PwH中BFR对低负荷（LL）膝盖伸展的急性发作期的神经肌肉和知觉反应。
方法：八个PwH进行了一次LL-BFR会话，动脉闭塞压（AOP）为40％。评估了感知反应和不良反应，以及股内侧肌（VM）和外侧肌（VL）的高密度表面肌电图。
结果：在每组中发现了显着的归一化均方根差异，但不是在集合之间。空间分布(质心位移(p>.05)，修正熵(VM，设置二，第三和第五周期，p=0.032)和变异系数(VM，设置二，低于第三周期的第四周期和第五周期(p=.049;p=.036))显示每组内的变化。中值频率显示在第4组的第4周期期间略有增加(p=.030)。每组运动的感知率略有增加，而最后一组的耐受性略有下降，训练结束后对BFR训练的恐惧通常会降低。
结论：在PwH中，40%AOP的LL-BFR会话是安全可行的。我们的结果表明，潜在的肌肉损伤可能会削弱BFR诱导的神经肌肉适应。
