Van Eijden T M, Brugman P, Weijs W A, Oosting J
Academic Center for Dentistry Amsterdam (ACTA), Department of Anatomy and Embryology, The Netherlands.
J Biomech. 1990;23(5):475-85. doi: 10.1016/0021-9290(90)90303-k.
The aim of this study was to obtain insight into the coactivation behaviour of the jaw muscles under various a priori defined static loading conditions of the mandible. As the masticatory system is mechanically redundant, an infinite number of recruitment patterns is theoretically possible to produce a certain bite force. Using a three-component force transducer and a feedback method, subjects could be instructed to produce a bite force of specific direction and magnitude under simultaneous registration of the EMG activity of anterior and posterior temporal, masseter and digastric muscles on each side. Forces were measured at the second premolars. Vertical, anterior, posterior, lateral and medial force directions were examined; in each direction force levels between 50 N and maximal voluntary force were produced. The results show that for all muscles the bite force-EMG relationship obeys a straight-line fit for forces exceeding 50 N. The relationship varies with bite force direction, except in the case of the digastric muscles. Variation is small for the anterior temporal and large for the posterior temporal and masseter muscles. The relative activation of muscles for a particular force in a particular direction in unique, despite the redundancy.
本研究的目的是深入了解在下颌骨各种先验定义的静态加载条件下，颌骨肌肉的共同激活行为。由于咀嚼系统在机械方面具有冗余性，理论上存在无数种募集模式来产生特定的咬合力。使用三分量力传感器和反馈方法，可以指示受试者在同时记录每侧颞肌前、后部、咬肌和二腹肌的肌电图活动的情况下，产生特定方向和大小的咬合力。在第二前磨牙处测量力。检查了垂直、前、后、外侧和内侧力方向；在每个方向上产生了50 N到最大自主力之间的力水平。结果表明，对于所有肌肉，咬合力-肌电图关系在力超过50 N时符合直线拟合。除二腹肌外，这种关系随咬合力方向而变化。颞肌前部的变化较小，颞肌后部和咬肌的变化较大。尽管存在冗余性，但在特定方向上针对特定力的肌肉相对激活情况是独特的。
