Carneiro J G, Gonçalves E M, Camata T V, Altimari J M, Machado M V, Batista A R, Guerra Junior G, Moraes A C, Altimari L R
Group of Study and Research in Neuromuscular System and Exercise, CEFE-State University of Londrina, Londrina, PR, Brazil.
Electromyogr Clin Neurophysiol. 2010 Nov-Dec;50(7-8):326-32.
The aim of this study was to investigate the influence of gender on the EMG signal of the muscles of the quadriceps femoris and the physical performance in high-intensity, short-term exercise. Fourteen volunteers (7 men = 29.1 +/- 2.8 years and 7 women = 22.6 +/- 2.9 years) performed a Wingate Test (WT) with a load of 7.5% of body mass. The variables analyzed during the WT were the Relative Peak Power (W.Kg(-1)) (RPP), Relative Mean Power (W.Kg(-1)) (RMP), Fatigue Index (%) (FI) and Peak Power Instant (s) (PPI). EMG signals of the superficial muscles of the quadriceps femoris (QF) from the right leg: rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) were analyzed through root mean square (RMS) values and the normalized median frequency (MNF) determined using the Fast Fourier Transform (FFT). The RPP and the RMP were significantly higher in men when compared to women (9.99 +/- 0.96 vs. 7.66 +/- 1.00 W.kg(-1); 7.23 +/- 0.49 vs. 5.65 +/- 0.61 W.kg(1), P < 0.05; respectively). No significant difference between genders was found on RMS and NMF during WT (P > 0.05). Although RPP and RMP were influenced by gender, the RMS and the NMF of the superficial muscles of the QF did not show the same behavior, suggesting that other mechanisms, not related to motor unit recruitment and speed of nervous stimuli in the muscle fiber may be associated to the lower performance of women in high-intensity, short-term exercise.
本研究旨在调查性别对股四头肌肌肉肌电图信号以及高强度、短期运动中身体表现的影响。14名志愿者（7名男性，年龄29.1±2.8岁；7名女性，年龄22.6±2.9岁）进行了负荷为体重7.5%的温盖特测试（WT）。在WT期间分析的变量包括相对峰值功率（W.Kg(-1)）（RPP）、相对平均功率（W.Kg(-1)）（RMP）、疲劳指数（%）（FI）和峰值功率瞬间（s）（PPI）。通过均方根（RMS）值分析右腿股四头肌（QF）表层肌肉：股直肌（RF）、股外侧肌（VL）和股内侧肌（VM）的肌电图信号，并使用快速傅里叶变换（FFT）确定归一化中位数频率（MNF）。与女性相比，男性的RPP和RMP显著更高（分别为9.99±0.96 vs. 7.66±1.00 W.kg(-1)；7.23±0.49 vs. 5.65±0.61 W.kg(1)，P<0.05）。在WT期间，性别之间在RMS和NMF上未发现显著差异（P>0.05）。尽管RPP和RMP受性别影响，但QF表层肌肉的RMS和NMF并未表现出相同的行为，这表明在高强度、短期运动中，女性表现较低可能与其他机制有关，这些机制与运动单位募集和肌肉纤维中神经刺激速度无关。
