The quadriceps-intermittent-fatigue (QIF) test assesses knee extensors strength, endurance and performance fatigability in isometric condition. We aimed to assess reliability and agreement for this test in dynamic conditions and with the use of transcranial magnetic stimulation. On two separate sessions, 20 young adults (25 ± 4 yr, 10 women) performed stages of 100 knee extensors concentric contractions at 120°/s (60° range-of-motion) with 10% increments of the initial maximal concentric torque until exhaustion. Performance fatigability across the test was quantified as maximal isometric and concentric torque loss, and its mechanisms were investigated through the responses to transcranial magnetic and electrical stimulations. Reliability and agreement were assessed using ANOVAs, coefficients of variation (CVs) and intra-class correlation coefficients (ICCs) with 95% CI. Good inter-session reliability and high agreement were found for number of contractions [489 ± 75 vs. 503 ± 95; P = 0.20; ICC = 0.85 (0.66; 0.94); CV = 5% (3; 7)] and total work [11,285 ± 4,932 vs. 11,792 ± 5838 Nm.s; P = 0.20; ICC = 0.95 (0.87; 0.98); CV = 8% (5; 11)]. Poor reliability but high agreement were observed for isometric [–33 ± 6 vs. −31 ± 7%; P = 0.13; ICC = 0.47 (0.05; 0.75); CV = 6% (4;8)] and concentric [−20 ± 11% vs. −19 ± 9%; P = 0.82; ICC = 0.26 (−0.22; 0.63); CV = 9% (6; 12)] torque loss. The dynamic QIF test represents a promising tool for neuromuscular evaluation in isokinetic mode.

股四头肌间歇性疲劳（QIF）测试可评估等轴测条件下膝关节伸肌的力量，耐力和表现疲劳性。我们旨在评估该测试在动态条件下以及经颅磁刺激的可靠性和一致性。在两个不同的阶段中，有20位年轻的成年人（25±4岁，10位女性）以120°/ s（60°的运动范围）以100％的初始最大同心扭矩增量执行100次伸膝同心收缩的阶段，直到精疲力尽。整个测试中的性能疲劳可量化为最大等距和同心扭矩损失，并通过对经颅磁刺激和电刺激的响应来研究其机理。使用ANOVA评估可靠性和一致性，变异系数（CV）和类内相关系数（ICC），CI为95％。会议期间的收缩次数[489±75]，具有良好的会话间可靠性和高度一致性与503±95；P = 0.20；ICC = 0.85（0.66; 0.94）；CV = 5％（3; 7）]，总功[11,285±4,932 vs. 11,792±5838 Nm.s; P = 0.20；ICC = 0.95（0.87; 0.98）；CV = 8％（5; 11）]。等轴测结果显示，可靠性较差，但一致性较高[–33±6 vs. -31±7％；P = 0.13；ICC = 0.47（0.05; 0.75）; CV = 6％（4; 8）]，同心度[−20±11％vs.− 19±9％；P = 0.82；ICC = 0.26（-0.22; 0.63）; CV = 9％（6; 12）]扭矩损失。动态QIF测试代表等速模式下神经肌肉评估的有前途的工具。