Cramer J T, Housh T J, Weir J P, Ebersole K T, Perry-Rana S R, Bull A J, Johnson G O
Department of Health and Human Performance, Center for Youth Fitness and Sports Research, University of Nebraska-Lincoln, Lincoln, NE 68588-0229, USA.
Electromyogr Clin Neurophysiol. 2003 Jul-Aug;43(5):293-300.
The purpose of this investigation was to examine the cross-correlation coefficients of mechanomyographic (MMG) signals recorded from the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles during maximal, concentric and eccentric isokinetic muscle actions. Eleven females (mean +/- SD age = 21 +/- 1 yr) performed such muscle actions of the leg extensors at 60 degrees.s-1 on a Cybex 6000 dynamometer. MMG signals were sampled simultaneously from the VL, RF, and VM at 1000 Hz by piezoelectric crystal contact sensors. Peak composite cross-correlation coefficients (rxy) and common variances (rxy2) were determined for each between-muscle comparison (VL vs. RF, VL vs. VM, and RF vs. VM). The results indicated peak cross-correlation coefficients ranging from rxy = 0.38 to 0.52, while common variances (rxy2) between signals ranged from 14% to 27% across all time lags (tau = -50...). In conjunction with other studies, these results suggested that despite the potential for some cross-talk, MMG measurements can be used to examine differences between the patterns of MMG amplitude and frequency responses of the superficial quadriceps femoris muscles.
本研究的目的是检测在最大等速向心和离心肌肉动作过程中，从股外侧肌（VL）、股直肌（RF）和股内侧肌（VM）记录的肌机械图（MMG）信号的互相关系数。11名女性（平均±标准差年龄=21±1岁）在Cybex 6000测力计上以60度·秒⁻¹的速度进行腿部伸肌的此类肌肉动作。通过压电晶体接触传感器以1000Hz的频率同时从VL、RF和VM采集MMG信号。对每对肌肉比较（VL与RF、VL与VM、RF与VM）确定峰值复合互相关系数（rxy）和共同方差（rxy²）。结果表明峰值互相关系数范围为rxy=0.38至0.52，而信号之间的共同方差（rxy²）在所有时间滞后（tau=-50...）范围内为14%至27%。结合其他研究，这些结果表明，尽管存在一些串扰的可能性，但MMG测量可用于检查股四头肌浅层MMG振幅和频率反应模式之间的差异。
