Stokes I A, Moffroid M S, Rush S, Haugh L D
Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington 05405.
Muscle Nerve. 1988 Apr;11(4):331-6. doi: 10.1002/mus.880110409.
Comparison was made between simultaneous recordings of the electromyogram (EMG) and acoustic myogram (AMG) signals and the torque produced by the lumbar erectores spinae muscles of three healthy subjects while they performed isometric contractions. Repeatability of each signal was studied. The AMG had a relationship to the torque which was more quadratic than linear, whereas that of the EMG was more linear. The coefficient of variability of residuals about a "best-fit" line was 8.55% for torque-increasing EMG recordings and 19.2% for torque-increasing AMG recordings. At the same torque, the EMG was on average about 10% greater for increasing-torque recordings than for decreasing-torque parts of the recordings, but the magnitude of the AMG signal was about 10% less. With repeated testing on the same day, the coefficient of variability of the signal/torque relationship (torque-increasing) was 9% for EMG and 23% for AMG signals. With long-term testing over 2 weeks these coefficients were 23 and 39%, respectively. Correlation analysis showed that the two signal/torque relationships varied independently of each other.
对三名健康受试者在进行等长收缩时，其竖脊肌产生的扭矩与肌电图（EMG）和声肌电图（AMG）信号的同步记录进行了比较。研究了每个信号的重复性。AMG与扭矩的关系更呈二次曲线而非线性，而EMG与扭矩的关系更呈线性。对于扭矩增加的EMG记录，围绕“最佳拟合”线的残差变异系数为8.55%，对于扭矩增加的AMG记录为19.2%。在相同扭矩下，对于扭矩增加的记录，EMG平均比记录中扭矩减小的部分大10%左右，但AMG信号的幅度小10%左右。在同一天进行重复测试时，信号/扭矩关系（扭矩增加）的变异系数对于EMG为9%，对于AMG信号为23%。在两周的长期测试中，这些系数分别为23%和39%。相关分析表明，两种信号/扭矩关系相互独立变化。
