Electromyographic analysis of the sternohyoid muscle and anterior belly of the digastric muscle in head and tongue movements.

The sternohyoid muscle and anterior belly of the left digastric muscle were electromyographically studied in 20 young adult volunteer individuals. A surface monopolar electrode and a needle monopolar electrode, inserted into the muscle mass 1.0 cm apart were employed. The muscles acted during the following movements of the tongue; protraction, lateral movements to either side, and placement of the tip of the tongue on the hard and soft palate. It was in the latter movement that the most significant action potentials of the sternohyoid muscle were observed, which coincided with a major displacement of the hyoid bone. Both muscles studied do not take part in the kinesiology of the head.