Measurement of evoked mechanomyogram in cycling exercise

The purpose of this study was to develop a measurement system for evoked mechanomyogram (MMG) in cycling exercise. Ergometric cycling was performed under two workloads (60 W and 90 W) at a pedal rate of 60 rpm. When a subject extended his knee to an 80-degree angle, electric stimulus was applied to the vastus lateralis muscle every second time, and an MMG was measured with a condenser microphone. The MMG system was identified using a singular value decomposition method. The natural frequency of the system was calculated from the poles of the transfer function. In conclusion, the transfer function of evoked MMGs was well identified with a third-order model. The natural frequency increased as the workload increased. An evoked MMG in cycling exercise could be measured with the developed system.