Centre for Musculoskeletal Research, University of Gävle, Box 7629, 907 12 Umea, Sweden.
Eur J Appl Physiol. 2011 Apr;111(4):647-58. doi: 10.1007/s00421-010-1688-z. Epub 2010 Oct 16.
The aim was to investigate the relationship between oxygen saturation (StO(2)%) measured with near-infrared spectroscopy (NIRS) and myoelectric activity (root mean square, RMS) for the extensor carpi radialis (ECR) and trapezius muscles. In addition, gender differences were examined for submaximal (10-70% MVC) and sustained (10% MVC for 5 min) isometric contractions. Thirteen males and 15 females participated. Changes in StO(2)% (∆StO(2)%) and RMS, expressed as percentages of maximum, were calculated for each submaximal contraction. A good correlation between ∆StO(2)% and RMS was seen for the ECR (r = -0.53) and a moderate correlation seen for the trapezius muscle (r = -0.44). The ANOVA showed a significant decrease in ECR-∆StO(2)% over force with females demonstrating a tendency for larger changes than males. ECR-RMS increased over force with no impact of gender. For the trapezius, ∆StO(2)% decreased over force but was not gender dependent. Trapezius-RMS increased over force with females demonstrating a tendency for greater change than males. For the sustained contraction, ECR-StO(2)% changed over time but was not gender dependent. ECR-RMS increased over time with females showing a greater response than males. Trapezius-StO(2)% changed over time and differed between genders, i.e., males increased while females decreased. RMS increased over time similarly for both genders. In conclusion, our data show that the ECR and trapezius aerobic demands during isometric contractions are negatively correlated to electromyography (EMG) RMS. The present study also suggests some gender specificity for forearm and shoulder myoelectric activity and oxygenation for submaximal and sustained contractions.
目的是研究近红外光谱（NIRS）测量的氧饱和度（StO(2)％）与伸腕肌（ECR）和斜方肌的肌电活动（均方根，RMS）之间的关系。此外，还检查了亚最大（10-70％MVC）和持续（10％MVC 持续 5 分钟）等长收缩的性别差异。共有 13 名男性和 15 名女性参加。计算了每个亚最大收缩的 StO(2)％（∆StO(2)％）和 RMS 的变化，以最大百分比表示。ECR 的 ∆StO(2)％和 RMS 之间存在良好的相关性（r = -0.53），斜方肌的相关性中等（r = -0.44）。方差分析显示 ECR-∆StO(2)％随力显著下降，女性的变化趋势大于男性。ECR-RMS 随力增加，不受性别影响。对于斜方肌，∆StO(2)％随力下降，但不受性别影响。斜方肌-RMS 随力增加，女性的变化趋势大于男性。对于持续收缩，ECR-StO(2)％随时间变化，但不受性别影响。ECR-RMS 随时间增加，女性的反应大于男性。斜方肌-StO(2)％随时间变化，且性别间存在差异，即男性增加，女性减少。RMS 随时间的增加对于两种性别都是相似的。总之，我们的数据表明，等长收缩期间 ECR 和斜方肌的需氧量与肌电图（EMG）RMS 呈负相关。本研究还表明，在亚最大和持续收缩时，前臂和肩部肌电活动和氧合存在一些性别特异性。
