We sought to evaluate sex-specific 1) muscle activation patterns, hemodynamics, and swelling responses to short-cycle repetitive fatigue; 2) relationships between muscular responses and perceived fatigability. Asymptomatic participants (N = 26, 13 females) completed a repetitive pointing task until 8/10 on the Borg CR10 scale. Upper trapezius (UT), supraspinatus (SUPRA), and biceps brachii (BIC) muscle activation, activation variability (CV), median power frequency (MdPF) and thickness, and UT oxygenation were recorded. Males had higher BIC CV, UT and SUPRA MdPF, and UT and BIC thickness. Longer time to fatigue-terminal was correlated to greater SUPRA activation increase (ρ = 0.624) and BIC MdPF decrease (ρ = -0.674) in males, while in females it was correlated to greater (ρ = -0.657) and lower (ρ = 0.683) decrease of SUPRA and BIC CV, respectively. Male’s greater increase in SUPRA thickness correlated to greater increase in UT thickness and tissue oxygenation index, and to lower increase of UT deoxyhemoglobin. Females’ greater decrease of SUPRA MdPF correlated to greater decrease of UT MdPF, while greater UT activation increase was related to lower UT thickness increase. Results suggest that despite comparable time to fatigue-terminal, males have greater force-generating capacity and neuromuscular reliance on recruitment and excitation rates, while females have greater reliance on activation variability. Further, there are relationships between hemodynamic and swelling patterns in males, while there are relationships between activation and swelling patterns in females. Although there were no differences in experimental task-induced changes, there are sex-specific relationships between muscular patterns and perceived fatigability, which may help explain sex-specific mechanisms of musculoskeletal disorders.

我们试图评估特定性别的 1) 肌肉激活模式、血流动力学和对短周期重复疲劳的肿胀反应；2) 肌肉反应和感知疲劳之间的关系。无症状的参与者（N = 26，13 名女性）在 Borg CR10 量表上完成了重复的指向任务，直到 8/10。记录上斜方肌 (UT)、冈上肌 (SUPRA) 和肱二头肌 (BIC) 肌肉激活、激活变异性 (CV)、中位功率频率 (MdPF) 和厚度以及 UT 氧合。男性具有更高的 BIC CV、UT 和 SUPRA MdPF，以及 UT 和 BIC 厚度。更长的疲劳终止时间与男性更大的 SUPRA 激活增加 (ρ = 0.624) 和 BIC MdPF 降低 (ρ = -0.674) 相关，而在女性中，它与更大 (ρ = -0.657) 和更低 (ρ = 0.683) SUPRA 和 BIC CV 的减少，分别。男性在 SUPRA 厚度上的较大增加与 UT 厚度和组织氧合指数的较大增加相关，并且与 UT 脱氧血红蛋白的增加较少相关。女性 SUPRA MdPF 的更大减少与 UT MdPF 的更大减少相关，而更大的 UT 激活增加与更低的 UT 厚度增加有关。结果表明，尽管与疲劳末期的时间相当，但男性具有更大的力量产生能力和神经肌肉对募集和兴奋率的依赖，而女性则更依赖于激活可变性。此外，男性的血流动力学和肿胀模式之间存在关系，而女性的激活和肿胀模式之间存在关系。虽然实验任务引起的变化没有差异，