Samulski Brittany, Prebor Jessica, Armitano Cortney, Morrison Steven
School of Physical Therapy and Athletic Training, Old Dominion University, United States.
Department of Communication Disorders and Special Education, Old Dominion University, United States.
Neurosci Lett. 2019 Apr 17;698:90-96. doi: 10.1016/j.neulet.2019.01.016. Epub 2019 Jan 8.
Chewing and walking are two oscillatory behaviors performed on an everyday basis. The current study examined the impact chewing at different speeds (i.e. fast, slow, preferred) had on walking performance for fifteen young healthy adults (23.2 + 4.2 years) and fifteen healthy older participants (66.5 + 3.2 years). Chewing rates were attained from surface EMG activity recorded from the masseter muscle. For gait, accelerometers mounted on the lower trunk and lower leg were used to determine the timing of individual steps. In addition, a pressure sensitive walkway was also used to collect gait metrics (i.e., gait velocity, step length, step time). Our results demonstrated a strong link between chewing and walking for all participants, with increases or decreases in a person's chewing rate leading to similar changes in their stepping rate (and hence walking speed). One explanation for this coupling is that the neural drive related to chewing entrains the muscles involved in the basic gait action of stepping. The coupling of stepping with chewing rates for all individuals was observed despite the older adults tending to walk slower overall. However, there were no age-related differences in chewing rates, suggesting that despite the general slowing of motor function seen with increasing age, mastication itself does not appear to be similarly affected.
咀嚼和行走是日常进行的两种节律性行为。本研究考察了不同速度（即快速、慢速、偏好速度）的咀嚼对15名年轻健康成年人（23.2±4.2岁）和15名健康老年人（66.5±3.2岁）行走表现的影响。咀嚼速率通过从咬肌记录的表面肌电图活动获得。对于步态，安装在下躯干和小腿上的加速度计用于确定各个步幅的时间。此外，还使用了压力感应步道来收集步态指标（即步态速度、步长、步时）。我们的结果表明，所有参与者的咀嚼和行走之间存在紧密联系，个体咀嚼速率的增加或减少会导致其步频（进而行走速度）发生类似变化。对此耦合现象的一种解释是，与咀嚼相关的神经驱动带动了参与基本步态动作（即迈步）的肌肉。尽管老年人总体上行走较慢，但所有个体的步幅与咀嚼速率之间的耦合现象均被观察到。然而，咀嚼速率不存在与年龄相关的差异，这表明尽管随着年龄增长运动功能普遍减缓，但咀嚼本身似乎并未受到类似影响。
