Human isometric force production and electromyogram activity of knee extensor muscles in water and on dry land
Human isometric force production and electromyogram activity of knee extensor muscles in water and on dry land
复制标题
水中和陆地上膝伸肌的人体等长力产生和肌电图活动
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
E. Mälkiä
中科院分区：
文献类型：
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作者：
T. Pöyhönen;K. Keskinen;Arto J Hautala;J. Savolainen;E. Mälkiä
摘要
本研究旨在确定膝关节伸肌在水中和陆地上等长收缩力和肌电图活动（EMG）的逐次试验和逐日重现性，并对两种训练条件下的肌肉活动和力量产生进行比较。20名健康受试者（12名女性和8名男性）在两周内接受了三次测试。一次测量包括记录最大和次最大等长膝关节伸展力，同时记录来自股内侧肌、股外侧肌和股二头肌的表面肌电图。为确保测量条件相同，在干燥和潮湿环境中均使用同一台患者升降椅。组内相关系数（ICC）和变异系数（CV）表明，在最大收缩期间，每种肌肉在水中和陆地上的力量和肌电图测量的逐次试验重现性（ICC = 0.95 - 0.99，CV = 3.5% - 11%）和逐日重现性（ICC = 0.85 - 0.98，CV = 11% - 19%）都很高。次最大收缩的逐日重现性相似。有趣的发现是，在最大收缩（P < 0.01 - P < 0.001）和次最大收缩（P < 0.05 - P < 0.001）期间，每种肌肉的水下肌电幅值均显著降低。然而，等长收缩力测量在潮湿和干燥条件下显示出相似的值。如电极间电阻值略有降低、无伪影以及肌电信号噪声水平低所示，水对电极没有干扰作用。结论是水下力量和肌电图测量具有高度重现性。水下肌电的显著降低可能有机电和/或神经生理学方面的解释。
Abstract This study was designed to determine trial-to-trial and day-to-day reproducibility of isometric force and electromyogram activity (EMG) of the knee extensor muscles in water and on dry land as well as to make comparisons between the two training conditions in muscle activity and force production. A group of 20 healthy subjects (12 women and 8 men) were tested three times over 2 weeks. A measurement session consisted of recordings of maximal and submaximal isometric knee extension force with simultaneous recording of surface EMG from the vastus medialis, vastus lateralis and biceps femoris muscles. To ensure identical measurement conditions the same patient elevator chair was used in both the dry and the wet environment. Intraclass correlation coefficients (ICC) and coefficients of variation (CV) showed high trial-to-trial (ICC=0.95–0.99, CV=3.5%–11%) and day-to-day reproducibility (ICC=0.85–0.98, CV=11%–19%) for underwater and dry land measurements of force and EMG in each muscle during maximal contractions. The day-to-day reproducibility for submaximal contractions was similar. The interesting finding was that underwater EMG amplitude decreased significantly in each muscle during maximal (P < 0.01–P < 0.001) and submaximal contractions (P < 0.05–P < 0.001). However, the isometric force measurements showed similar values in both wet and dry conditions. The water had no disturbing effect on the electrodes as shown by slightly lowered interelectrode resistance values, the absence of artefacts and low noise levels of the EMG signals. It was concluded that underwater force and EMG measurements are highly reproducible. The significant decrease of underwater EMG could have electromechanical and / or neurophysiological explanations.