Larsson B, Karlsson S, Eriksson M, Gerdle B
Department of Rehabilitation Medicine, INR, Faculty of Health Sciences, Linköping, Sweden.
J Electromyogr Kinesiol. 2003 Jun;13(3):281-7. doi: 10.1016/s1050-6411(03)00022-1.
The aim of this study was to investigate the reliability of peak torque and surface electromyography (EMG) variable's root mean square (RMS) and mean frequency (MNF) during an endurance test consisting of repetitive maximum concentric knee extensions. Muscle fatigue has been quantified in several ways, and in isokinetic testing it is based on a set of repetitive contractions. To assess test-retest reliability, two sets of 100 dynamic maximum concentric knee extensions were performed using an isokinetic dynamometer. The two series were separated by 7-8 days. The subjects relaxed during the passive flexion phase. Twenty (10 men and 10 women) clinically healthy subjects volunteered. Peak torque and EMG from rectus femoris, vastus medialis, vastus lateralis and biceps femoris were recorded. RMS and MNF were calculated from the EMG signal. The reliability was calculated with intraclass correlation coefficient ICC (1.1) and standard error of measurements (SEM). The reliability of peak torque was good (ICC=0.93) and SEM showed low values. ICC was good for absolute RMS of rectus femoris (ICC>/=0.80), vastus medialis (ICC>/=0.88) and vastus lateralis (ICC>/=0.82) and MNF of rectus femoris (ICC>/=0.82) and vastus medialis (ICC>/=0.83). Peak torque, and MNF and RMS of rectus femoris and vastus medialis are reliable variables obtained from an isokinetic endurance test of the knee extensors.
本研究的目的是调查在由重复性最大向心膝关节伸展组成的耐力测试期间，峰值扭矩以及表面肌电图（EMG）变量的均方根（RMS）和平均频率（MNF）的可靠性。肌肉疲劳已经通过多种方式进行量化，在等速测试中，它基于一组重复性收缩。为了评估重测可靠性，使用等速测力计进行了两组100次动态最大向心膝关节伸展。这两组测试间隔7 - 8天。在被动屈曲阶段，受试者保持放松。20名（10名男性和10名女性）临床健康受试者自愿参与。记录了股直肌、股内侧肌、股外侧肌和股二头肌的峰值扭矩和肌电图。从肌电图信号计算均方根和平均频率。可靠性通过组内相关系数ICC（1.1）和测量标准误差（SEM）进行计算。峰值扭矩的可靠性良好（ICC = 0.93），测量标准误差显示值较低。股直肌（ICC≥0.80）、股内侧肌（ICC≥0.88）和股外侧肌（ICC≥0.82）的绝对均方根以及股直肌（ICC≥0.82）和股内侧肌（ICC≥0.83）的平均频率的组内相关系数良好。峰值扭矩以及股直肌和股内侧肌的平均频率和均方根是从膝关节伸肌的等速耐力测试中获得的可靠变量。
