Miralles R, Palazzi C, Ormeño G, Giannini R, Verdugo F, Valenzuela S, Santander H
Oral Physiology Laboratory, Faculty of Medicine, University of Chile, Santiago.
Cranio. 1998 Apr;16(2):90-9. doi: 10.1080/08869634.1998.11746045.
This study was conducted in order to determine the effects of body position on integrated electromyographic (IEMG) activity of sternocleidomastoid and masseter muscles in 20 healthy subjects. EMG recordings at rest and during swallowing of saliva and maximal voluntary clenching were performed by placing surface electrodes on the sternocleidomastoid and masseter muscles (contralateral to the habitual side of sleeping of each subject), in the following body positions: standing, seated, supine, and lateral decubitus position. Significant higher EMG activities were recorded in the sternocleidomastoid muscle in the lateral decubitus position, whereas significant lower EMG activities were recorded in the masseter muscle in the supine position. This finding supports the idea that there may exist a differential modulation of the motor neuron pools of the sternocleidomastoid and masseter muscles of peripheral and/or central origin. Significant differences in the EMG pattern as well as in the levels of EMG activities upon variations in body positions were observed between healthy subjects and patients with myogenic craniomandibular dysfunction reported by Palazzi, et al.
本研究旨在确定身体姿势对20名健康受试者胸锁乳突肌和咬肌的肌电积分（IEMG）活动的影响。通过将表面电极置于胸锁乳突肌和咬肌（与每个受试者习惯睡眠侧对侧）上，在以下身体姿势下进行静息、吞咽唾液和最大自主紧咬时的肌电图记录：站立、坐位、仰卧位和侧卧位。侧卧位时胸锁乳突肌记录到显著更高的肌电活动，而仰卧位时咬肌记录到显著更低的肌电活动。这一发现支持了这样一种观点，即胸锁乳突肌和咬肌的运动神经元池可能存在外周和/或中枢来源的差异调节。Palazzi等人报告的健康受试者和肌源性颅下颌功能障碍患者之间，在身体姿势变化时，肌电图模式以及肌电活动水平存在显著差异。
