Zafar H, Nordh E, Eriksson P-O
Department of Odontology, Clinical Oral Physiology, Umeå University, Umeå, Sweden.
Exp Brain Res. 2002 Sep;146(1):70-6. doi: 10.1007/s00221-002-1157-y. Epub 2002 Jun 19.
Previous studies of spatial and temporal coordination between human mandibular and head-neck movements during single as well as rhythmic jaw opening-closing tasks suggest that these movements are regulated by central nervous commands common for jaw and neck muscles. The present study evaluated the spatiotemporal consistency of concomitant mandibular and head-neck movements during repeated single jaw opening-closing tasks, in short- as well as long-term perspectives and at different speeds. The subjects were seated in an upright position without head support. They were instructed to perform single maximal jaw opening-closing movements, repeated ten times for fast and slow speed, respectively. Recordings were made at two sessions. A wireless optoelectronic technique was used to record three-dimensional mandibular and head-neck movements. The spatiotemporal consistency of repeated movement trajectories of the mandible (both in relation to the head and in space) and of the head-neck was quantitatively assessed by a spatiotemporal index (STI). In addition, mean movement trajectory patterns were compared for speed and recording sessions (expressed as correlation coefficient, r). The results showed relatively small STI (high degree of spatiotemporal consistency) and high r (reproducible trajectory patterns) values, both in short- and long-term perspectives, for concomitant mandibular and head-neck movements. The data were not generally speed related. In conclusion, the present results suggest a high degree of spatiotemporal consistency of the kinematic patterns of mandibular and head-neck movements during jaw opening-closing, in short- as well as long-term perspectives. They also indicate that underlying neural processes are invariant in nature. The results give further support to the notion of a tight functional coupling between the human jaw and the neck motor systems during natural jaw function.
以往关于人类在单次以及有节奏的下颌开合任务中，下颌与头颈运动之间的空间和时间协调性的研究表明，这些运动受下颌和颈部肌肉共有的中枢神经指令调节。本研究从短期和长期视角以及不同速度，评估了在重复的单次下颌开合任务中，下颌与头颈伴随运动的时空一致性。受试者直立就座，头部无支撑。他们被要求分别以快速和慢速进行单次最大程度的下颌开合运动，各重复十次。在两个时间段进行记录。采用无线光电技术记录下颌和头颈的三维运动。通过时空指数（STI）定量评估下颌（相对于头部以及在空间中的）重复运动轨迹与头颈重复运动轨迹的时空一致性。此外，比较了不同速度和记录时间段的平均运动轨迹模式（以相关系数r表示）。结果显示，无论是短期还是长期视角，下颌与头颈伴随运动的时空指数（STI）相对较小（时空一致性程度高），相关系数r较高（轨迹模式可重复）。数据一般与速度无关。总之，本研究结果表明，在短期和长期视角下，下颌开合过程中下颌与头颈运动学模式具有高度的时空一致性。它们还表明潜在的神经过程本质上是不变的。这些结果进一步支持了在自然下颌功能过程中，人类下颌与颈部运动系统之间存在紧密功能耦合这一观点。
