Oliveira A S C, Gonçalves M
Biomechanics Laboratory, Department of Physical Education, Biosciences Institute, São Paulo State University, Rio Claro, São Paulo, Brazil.
Electromyogr Clin Neurophysiol. 2009 Mar-Apr;49(2-3):93-101.
This study aimed to compare the torque, torque ratio (Hamstrings: Quadriceps - H:Q), electromyographic (EMG) activity and EMG ratio (knee flexors: knee extensors EMG) in soccer players (SG, N = 10) and active subjects (AG, N = 10). Subjects performed three maximal voluntary isometric knee extensions and flexions at 45 degrees and 90 degrees to determine the peak torque and EMG activity. Torque and EMG activity of the knee flexor (biceps femoris [BF] and semitendinosus [ST]) were divided by the torque and EMG activity of the knee extensor (vastuls lateralis [VL] and rectus femoris [RF]) to calculate torque ratios (H:Q) and EMG ratios (BF:VL, BF:RF, ST:VL, ST:RF). The flexion torque was significantly higher for SG (p < 0.05) in 45 degrees and 90 degrees. EMG activity for SG was significantly higher in agonist contractions for VL, RF and ST and significantly lower in antagonist contractions for RF and ST when compared to AG. Torque and EMG ratios were similar between groups and there were good correlations between torque ratio and BF:VL ratio (r = 0.71, p = 0.02) and BF:RF ratio (r = 0.81, p = 0.004) at 45. The EMG results could overestimate the joint balance calculated using torque ratios. Differences in recruitment pattern between soccer players and non-athletes can be related to the training routines and the EMG ratios presents applicable in trained populations.
本研究旨在比较足球运动员（SG组，N = 10）和活跃受试者（AG组，N = 10）的扭矩、扭矩比（腘绳肌：股四头肌 - H:Q）、肌电图（EMG）活动及EMG比（膝屈肌：膝伸肌EMG）。受试者在45度和90度进行三次最大自主等长膝关节伸展和屈曲，以确定峰值扭矩和EMG活动。将膝屈肌（股二头肌[BF]和半腱肌[ST]）的扭矩和EMG活动除以膝伸肌（股外侧肌[VL]和股直肌[RF]）的扭矩和EMG活动，以计算扭矩比（H:Q）和EMG比（BF:VL、BF:RF、ST:VL、ST:RF）。SG组在45度和90度时的屈曲扭矩显著更高（p < 0.05）。与AG组相比，SG组在VL、RF和ST的主动肌收缩时EMG活动显著更高，而在RF和ST的拮抗肌收缩时EMG活动显著更低。两组之间的扭矩和EMG比相似，且在45度时扭矩比与BF:VL比（r = 0.71，p = 0.02）和BF:RF比（r = 0.81，p = 0.004）之间存在良好的相关性。EMG结果可能高估了使用扭矩比计算的关节平衡。足球运动员和非运动员之间募集模式的差异可能与训练常规有关，且EMG比在受过训练的人群中具有适用性。
