Abstract
A mechanomyogram (MMG) in walking consists of not only the evoked MMG but also acceleration caused by the body motion. The purpose of this study is to estimate the elasticity of the anterior tibial muscle in walking from the evoked MMG by eliminating the motion acceleration with a Kalman filter.
Electrical stimulation was applied to the common peroneal nerve every twice at heel contact, and the MMG was measured. The evoked MMG in walking was extracted with a Kalman filter. The system from the electrical stimulation to the evoked MMG was identified using a singular value decomposition method. The natural frequency of the system was calculated from the poles of the identified transfer function. The natural frequency of the evoked MMG in resting was also calculated.
In conclusion, transfer functions of evoked MMGs in walking and resting were approximated with the sixth-order model. The natural frequency in walking was higher than that in resting. It was concluded that the elasticity of the anterior tibial muscle increased at heel contact.
