咀嚼筋と四肢筋の疲労とその回復に関する研究
1998 年 42 巻 1 号 p. 115-123
詳細
1998 年 42 巻 1 号 p. 115-123
The purpose of this investigation was to elucidate the fatigue characteristics of the masticatory muscles. In five healthy, fully dentate male subjects, maximalvoluntary isometric bite force and elbow flexion and knee extension isometric strength were registered with the Dental Prescale System and a load cell. Simultaneously, the electromyographic activity from the masseter, temporal, biceps brachial and rectus femoral muscles was recorded using the Multi-Telemeter System. A protocol involving three 5-second and three 30-second isometric contractions with 10-second rest periods in between was designed to induce fatigue. The 5-secondisometric contractions were compared to a control with the initial duration of 5seconds that was recorded at the beginning of the protocol. The integrated EMG and their peak frequency of power spectrum was calculated.
The results were asfollows:
1. In the masticatory muscles the integrated EMG decreased with muscle fatigue.
2. In all the muscles, a shift in the peak frequency of the EMG power spectrum was observed according to the state of the muscle, lower values inthe fatigue phase, and higher values in the recovery stage.
3. The muscle force/integrated EMG ratio of the masseter and temporal muscles showed higher values than the biceps brachial and rectus femoral muscles.
