Research Group Biomechanics, Institute for Mechanics, University of Karlsruhe, Karlsruhe, Germany.
J Oral Rehabil. 2010 May 1;37(5):329-35. doi: 10.1111/j.1365-2842.2010.02064.x. Epub 2010 Feb 18.
Neuromuscular interaction between neck and jaw muscles has been reported in several studies. However, the influence of experimentally modified posture of the neck on jaw muscle activity during isometric biting was not investigated so far. The aim of the present study was to test by the aid of simultaneous electromyographic and intraoral bite force measurements whether neck rotation and lateroflexion, in contrast to a straightforward neck position, change the isometric cocontraction patterns of masticatory muscles under identical submaximum bite forces of 50-200 N. Electric muscle activity of all masticatory muscles and changes of the reduction point (RP) of the resultant bite force vectors were examined. An anteroposterior displacement of the RPs could be observed for the rotated and lateroflexed neck position in comparison with the straightforward position. On the other hand, the results revealed no significant differences between bilateral muscle activation under the different test conditions. These findings suggest a force transmission between the neck and the masticatory system, but no essential activity changes in the masticatory muscles under short time posture modification of the neck.
已有多项研究报告称颈部和颌部肌肉之间存在神经肌肉相互作用。然而，迄今为止，尚未研究实验性改变颈部姿势对等长咀嚼时颌部肌肉活动的影响。本研究旨在通过同时进行肌电图和口腔内咬合力测量来测试，与直接的颈部姿势相比，颈部旋转和侧屈是否会在相同的亚最大咬合力 50-200 N 下改变咀嚼肌的等长协同收缩模式。研究了所有咀嚼肌的电肌活动和合力矢量的还原点 (RP) 的变化。与直接位置相比，旋转和侧屈的颈部位置可观察到 RP 的前后位移。另一方面，结果表明，在不同的测试条件下，双侧肌肉激活没有显著差异。这些发现表明颈部和咀嚼系统之间存在力传递，但在颈部短时间姿势改变下，咀嚼肌的活动没有明显变化。
