Abstract
[Purpose] To clarify the influences of neck and shoulder postures on the regional ventilation and rib cage-abdominal volumes in a supine position. [Subjects and Methods] Measurement was performed in 15 healthy young males who adopted 6 postures combining the following tasks in a supine position: maintaining the neck neutral, rotating it at 60°, and abducting the shoulder at 10°, 90°, or 135°. The participants breathed at rest with a pneumotachometer attached, and their respiration-related rib cage and abdominal movements were analyzed using a 3-dimensional motion analysis device. The rib cage-abdominal region was divided into 6 sections: the left and right upper thoraxes, lower thoraxes, and abdomens. The tidal volume (VT), end-expiratory rib cage-abdominal volume (EERAV), and EERAV in each section were calculated using Excel VBA. [Results] On examining the EERAV in each section, the value in the ipsilateral lower thorax was significantly higher when abducting the shoulder at 135° compared with 10°. Neither the VT nor EERAV was influenced by neck or shoulder postures. [Conclusion] A shoulder abduction angle of 135° may increase the end-expiratory lung volume in the ipsilateral lower thorax.
