Morrish G M, Woledge R C, Haddad F S
UCL Institute of Human Performance, Royal National Orthopaedic Hospital Trust, Brockley Hill, Stanmore, Middlesex HA7 4LP, United Kingdom.
Electromyogr Clin Neurophysiol. 2003 Jul-Aug;43(5):259-65.
The purpose of this study was to evaluate individual differences in three parts of the quadriceps activated isometrically at 60 degrees and 90 degrees of knee flexion, and during a functional activity involving both concentric and eccentric muscle work. Surface EMG amplitudes were therefore recorded from oblique parts of vastus medialis (VMO) and vastus lateralis (VLO) and from rectus femoris (RF). VMO and VLO showed less activation at 60 degrees than at 90 degrees, but in RF there was no difference between the two angles. In the second experiment, where 11 subjects stepped on and off a stool; these amplitudes were compared with those from a maximal isometric voluntary contraction at 90 degrees of knee flexion. For VMO & VLO the normalised peak amplitude in stepping up was 1.41 +/- 0.12, & 1.46 +/- 0.15 respectively, showing that higher activity is necessary during concentric contractions. These two results suggest that the motor control of VMO/VLO may be different from the bulk of quadriceps. Our findings have implications for patellofemoral function.
本研究的目的是评估在膝关节屈曲60度和90度等长收缩时以及在涉及向心和离心肌肉工作的功能活动中，股四头肌三个部分的个体差异。因此，从股内侧肌（VMO）和股外侧肌（VLO）的斜部以及股直肌（RF）记录表面肌电图振幅。VMO和VLO在60度时的激活程度低于90度，但RF在这两个角度之间没有差异。在第二个实验中，11名受试者上下一个凳子；将这些振幅与膝关节屈曲90度时最大等长自主收缩的振幅进行比较。对于VMO和VLO，上台阶时的标准化峰值振幅分别为1.41±0.12和1.46±0.15，表明向心收缩期间需要更高的活动水平。这两个结果表明，VMO/VLO的运动控制可能与大部分股四头肌不同。我们的研究结果对髌股功能有影响。
