Relationship between Muscle Fiber Conduction Velocity and the Force-time Curve during Muscle Twitches

[Purpose] The aim of this study was to clarify the relationship between the muscle fiber conduction velocity (MFCV) obtained during muscle twitches from evoked potentials and the dynamic characteristics of muscular tension (muscle dynamic characteristics) by manipulating deep temperature. [Subjects] Subjects were 10 healthy adult men. Their mean age was 23.0 ± 3.9 years. [Methods] Measurement items were MFCV of the right tibialis anterior muscle and the force-time curve of right ankle dorsiflexion (muscle twitch). Measurements were made under conditions of ordinary (room) temperature, hot and cold. The rate of change in maximum torque was calculated from the force-time curve. [Results] In all subjects, MFCV increased significantly with heating and decreased significantly with cooling. A strong correlation was seen between MFCV and deep temperature. A strong correlation was also seen between MFCV and the rate of change in maximum torque. Stronger correlations were seen in the present results than in previous studies that conducted investigations using voluntary contractions. [Conclusion] The present results were not affected by psychological or other such factors, and are valuable as data with high physiological reliability. In conclusion, this study was able to clarify the relationship between MFCV from evoked potentials and muscle dynamic characteristics.