Evaluation of muscle fatigue in the masseter muscle using a tactile sensor

Abstract

It is difficult to evaluate muscle fatigue in masticatory muscles because they differ considerably from other skeletal muscles in structure and function.We analyzed muscle fatigue in the masseter muscle after mastication using a newly developed tactile sensor and clarified that the muscle stiffness increases and elasticity decreases as the number of masticatory cycles increases.Frequency analysis of the electromyogram to evaluate muscle fatigue showed that increasing the number of masticatory cycles decreased the higher frequency components of the electromyogram.However, changes in this parameter were not as pronounced as those in the muscle stiffness and elasticity as measured with the tactile sensor.