Send to:

Choose Destination
See comment in PubMed Commons below
Am Rev Respir Dis. 1991 Oct;144(4):845-7.

The effect of posture on upper airway dimensions in normal subjects and in patients with the sleep apnea/hypopnea syndrome.

Author information

  • 1Department of Medicine, City Hospital, Edinburgh, United Kingdom.


The effect of posture on upper airway dimensions was assessed for two reasons. First, some patients with untreated sleep apnea/hypopnea syndrome (SAHS) report they sleep better sitting upright. Second, to allow comparison of the differing techniques used to determine the site of maximal airway narrowing in awake patients with SAHS, as some are carried out in the erect and others in the supine posture. Lateral cephalometry was therefore carried out in 33 nonsnoring normal subjects and in 29 patients with obstructive SAHS (mean apneas plus hypopneas, 46 per hour; range, 17 to 103). In both normal subjects and patients, uvular width was increased (p less than 0.05) in the supine posture, and this was associated with significant narrowing of the retropalatal airway in the patients with SAHS (erect, 5.0 +/- SD 2.6 mm; supine, 3.6 +/- 2.8 mm; p less than 0.01). In both normal subjects and patients, the retroglossal hypopharynx widened (p less than 0.05) in the supine posture (e.g., in patients with SAHS, posterior airway space was: erect, 11.5 +/- 4.5 mm; supine, 13.4 +/- 4.8 mm; p = 0.003). In the supine posture there was anterior movement of the hyoid and neck flexion in both groups. However, a study of the effect of neck flexion in the erect posture showed that neck flexion produced no changes in airway caliber. Thus, posture is an important determinant of upper airway dimensions.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Atypon
    Loading ...
    Write to the Help Desk