Effects of XXXX and body position on bilateral sternocleidomastoid EMG activity.

@entity432 @entity235 @entity2798
This study was conducted to determine the effects of @entity432 and body position on bilateral sternocleidomastoid electromyographic (EMG) activity. The study was performed on 20 healthy subjects with natural dentition and bilateral molar support. During @entity432 (working side), each individual had to present @entity235 guidance on one side and group function on the opposite side, without balancing-side contacts. Integrated EMG (IEMG) recordings were performed by placing bipolar surface electrodes on the right and left sternocleidomastoid muscles. IEMG activity was recorded seated upright with the head unsupported and in the right and the left lateral decubitus body positions (head, neck and body horizontally aligned), under the following experimental conditions: 1. Maximal @entity2798 in the intercuspal position; 2. Laterotrusive occlusal excursion with @entity235 guidance; 3. Laterotrusive occlusal excursion with group function. Bilateral sternocleidomastoid IEMG activity with @entity235 guidance or group function was significantly lower than the intercuspal position in both body positions. In the seated upright position, significantly lower activity was observed with @entity235 guidance than in group function. In the lateral decubitus position activity was similar with both laterotrusive occlusal schemes and significantly higher than seated upright. Results suggest that both @entity432 and body position have significant influence on sternocleidomastoid IEMG activity. The clinical relevance of both factors is discussed.
