Electromyographic response of the inferior head of the human lateral pterygoid muscle to lateral inclination of the head and changes in posture

Abstract

To clarify the mechanism controlling human mandibular position as a function of lateral inclination of the head and body, I carried out electromyographic investigations of the muscle activities of the inferior head of the lateral pterygoid muscle under different postures with respect to the frontal plane. When the head leaned left or right, the lower jaw was displaced towards the inclination, and muscle activities on the ipsilateral side increased. These results indicate that reflection muscle activities have some control over the displaced condyle.