McGill S, Juker D, Kropf P
Department of Kinesiology, University of Waterloo, Canada.
J Biomech. 1996 Nov;29(11):1503-7. doi: 10.1016/0021-9290(96)84547-7.
This study tested the possibility of obtaining the activity of deeper muscles in the torso-specifically psoas, quadratus lumborum, external oblique, internal oblique and transverse abdominis, using surface myoelectric electrodes. It was hypothesized that: (1) surface electrodes adequately represent the amplitude of deep muscles (specifically psoas, quadratus lumborum, external oblique, internal oblique, transverse abdominis); (2) a single surface electrode location would best represent the activation profiles of each deep muscle over a broad variety of tasks. We assumed that prediction of activation within 10% of maximum voluntary contraction (RMS difference between the surface and intramuscular channels), over the time history of the signal, was reasonable and acceptable to assist clinical interpretation of muscle activation amplitude, and ultimately for modeled estimates of muscle force. Surface electrodes were applied and intramuscular electrodes were inserted on the left side of the body in five men and three women who then performed a wide variety of flexor tasks (bent knee and straight leg situps and leg raises, curl ups), extensor tasks (including lifting barbells up to 70 kg), lateral bending tasks (standing lateral bend and horizontal lying side support), twisting tasks (standing and sitting), and internal/external hip rotation. Using the criteria of RMS difference and the coefficient of determination (R2) to compare surface with intramuscular myoelectric signals, the results indicated that selected surface electrodes adequately represent the amplitude of deep muscles-always within 15% RMS difference, or less with the exception of psoas where differences up to 20% were observed but only in certain maximum voluntary contraction efforts. It appears reasonable for spine modelers, and particularly clinicians, to assume well selected surface electrode locations provide a representation of these deeper muscles-as long as they recognize the magnitude of error for their particular application.
本研究测试了使用表面肌电电极获取躯干深层肌肉（具体为腰大肌、腰方肌、腹外斜肌、腹内斜肌和腹横肌）活动的可能性。研究假设如下：（1）表面电极能够充分代表深层肌肉（具体为腰大肌、腰方肌、腹外斜肌、腹内斜肌、腹横肌）的幅度；（2）单个表面电极位置能在各种任务中最佳地代表每块深层肌肉的激活情况。我们认为，在信号的时间历程上，预测最大自主收缩的10%以内的激活情况（表面和肌内通道之间的均方根差）对于辅助临床解释肌肉激活幅度是合理且可接受的，最终对于肌肉力量的建模估计也是如此。在5名男性和3名女性身体左侧应用表面电极并插入肌内电极，然后他们进行了各种屈曲任务（屈膝和直腿仰卧起坐及抬腿、卷腹）、伸展任务（包括举起重达70千克的杠铃）、侧弯任务（站立侧弯和水平侧卧位支撑）、扭转任务（站立和坐着）以及髋部内/外旋转。使用均方根差标准和决定系数（R2）来比较表面肌电信号和肌内肌电信号，结果表明，选定的表面电极能够充分代表深层肌肉的幅度——均方根差始终在15%以内，腰大肌除外，在某些最大自主收缩努力中观察到的差异高达20%。对于脊柱建模者，尤其是临床医生而言，只要他们认识到特定应用中的误差大小，假设精心选择的表面电极位置能够代表这些深层肌肉似乎是合理的。
