Cramer Joel T, Housh Terry J, Weir Joseph P, Johnson Glen O, Berning Joseph M, Perry Sharon R, Bull Anthony J
Department of Health and Human Performance, Center for Youth Fitness and Sports Research, University of Nebraska-Lincoln, Lincoln, NE 68588-0229, USA.
Scand J Med Sci Sports. 2004 Apr;14(2):116-27. doi: 10.1111/j.1600-0838.2003.00317.x.
The purpose of this study was to examine the responses of peak torque (PT), mean power output (MP), mechanomyographic (MMG) and electromyographic (EMG) amplitude and mean power frequency (MPF) of the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) in males and females during maximal, concentric isokinetic muscle actions. Subjects performed maximal leg extensions at 60 degrees s(-1), 120 degrees s(-1), 180 degrees s(-1), 240 degrees s(-1), 300 degrees s(-1), 360 degrees s(-1), 420 degrees s(-1), and 480 degrees s(-1). No gender differences were observed, but there were muscle-specific differences for the patterns of MMG MPF, EMG amplitude, and EMG MPF. The MP and MMG amplitude increased to 180-240 degrees s(-1), plateaued, and then decreased to 480 degrees s(-1). MMG MPF for the VL and VM remained unchanged to 300 degrees s(-1), but then increased to 480 degrees s(-1). The EMG amplitude for the RF and EMG MPF for the VL decreased across velocity. Overall, these findings indicated that there were muscle-specific, velocity-related differences in the associations among motor control strategies (EMG amplitude and MPF) and the mechanical aspects of isokinetic muscular activity (MMG amplitude and MPF).
本研究的目的是检测男性和女性在最大程度的、向心等速肌肉动作过程中，股外侧肌（VL）、股直肌（RF）和股内侧肌（VM）的峰值扭矩（PT）、平均功率输出（MP）、肌机械图（MMG）和肌电图（EMG）幅度以及平均功率频率（MPF）的反应。受试者在60°/s、120°/s、180°/s、240°/s、300°/s、360°/s、420°/s和480°/s的速度下进行最大程度的腿部伸展。未观察到性别差异，但MMG MPF、EMG幅度和EMG MPF模式存在肌肉特异性差异。MP和MMG幅度增加至180 - 240°/s，达到平稳状态，然后降至480°/s。VL和VM的MMG MPF在300°/s之前保持不变，但随后增加至480°/s。RF的EMG幅度和VL的EMG MPF随速度增加而降低。总体而言，这些发现表明，在运动控制策略（EMG幅度和MPF）与等速肌肉活动的力学方面（MMG幅度和MPF）之间的关联中，存在肌肉特异性的、与速度相关的差异。
