Cai Mingshu, Brown Elizabeth C, Hatt Alice, Cheng Shaokoon, Bilston Lynne E
Neuroscience Research Australia and University of New South Wales, Sydney, Australia.
Neuroscience Research Australia and University of New South Wales, Sydney, Australia
J Appl Physiol (1985). 2016 Apr 1;120(7):758-65. doi: 10.1152/japplphysiol.00382.2015. Epub 2016 Jan 21.
Head and jaw position influence upper airway patency and electromyographic (EMG) activity of the main upper airway dilator muscle, the genioglossus. However, it is not known whether changes in genioglossus EMG activity translate into altered muscle movement during respiration. The aim of this study was to determine the influence of head and jaw position on dilatory motion of the genioglossus in healthy adult men during quiet breathing by measuring the displacement of the posterior tongue in six positions--neutral, head extension, head rotation, head flexion, mouth opening, and mandibular advancement. Respiratory-related motion of the genioglossus was imaged with spatial modulation of magnetization (SPAMM) in 12 awake male participants. Tissue displacement was quantified with harmonic phase (HARP) analysis. The genioglossus moved anteriorly beginning immediately before or during inspiration, and there was greater movement in the oropharynx than in the velopharynx in all positions. Anterior displacements of the oropharyngeal tongue varied between neutral head position (0.81 ± 0.41 mm), head flexion (0.62 ± 0.45 mm), extension (0.39 ± 0.19 mm), axial rotation (0.39 ± 0.2 mm), mouth open (1.24 ± 0.72 mm), and mandibular advancement (1.08 ± 0.65 mm). Anteroposterior displacement increased in the mouth-open position and decreased in the rotated position relative to cross-sectional area (CSA) (P = 0.002 and 0.02, respectively), but CSA did not independently predict anteroposterior movement overall (P = 0.057). The findings of this study suggest that head position influences airway dilation during inspiration and may contribute to variation in airway patency in different head positions.
头部和下颌位置会影响上呼吸道通畅性以及主要的上呼吸道扩张肌——颏舌肌的肌电图（EMG）活动。然而，尚不清楚颏舌肌EMG活动的变化是否会转化为呼吸过程中肌肉运动的改变。本研究的目的是通过测量后舌在六个位置（中立位、头部伸展、头部旋转、头部屈曲、张口和下颌前突）的位移，来确定头部和下颌位置对健康成年男性安静呼吸时颏舌肌扩张运动的影响。对12名清醒男性参与者进行了空间调制磁化（SPAMM）成像，以观察与呼吸相关的颏舌肌运动。采用谐波相位（HARP）分析对组织位移进行量化。颏舌肌在吸气前或吸气过程中立即开始向前移动，在所有位置，口咽部的移动都比软腭部更大。口咽部舌的向前位移在中立头位（0.81±0.41毫米）、头部屈曲（0.62±0.45毫米）、伸展（0.39±0.19毫米）、轴向旋转（0.39±0.2毫米）、张口（1.24±0.72毫米）和下颌前突（1.08±0.65毫米）之间有所不同。相对于横截面积（CSA），张口位的前后位移增加，旋转位的前后位移减少（分别为P = 0.002和0.02），但CSA总体上并不能独立预测前后运动（P = 0.057）。本研究结果表明，头部位置会影响吸气时气道扩张，可能导致不同头部位置的气道通畅性变化。
