Effects of Sitting Position on Volumes of Hemithoraces of Healthy Men and a Patient Who Underwent Thoracotomy With a Midline Incision

Abstract

Background:

Post-thoracotomy patients may acquire restrictive lung expansion due to poor posture. It is important to understand thoracic configuration and chest movement.

Methods:

One post-thoracotomy patient with a midline incision and 11 men were tested in upright and stooped sitting positions during quiet and volitional deep breathing. A total of 84 infrared reflective markers were placed on the anterior and posterior aspects of the trunk to record thoracic volume. The positioning for these markers was from 6 midline markers placed in a vertical line on 6 levels. This was repeated on the posterior aspect of the trunk. The anterior half was encompassed within the upper thorax demarcated by the sternal notch and 3rd rib, and the posterior half within the lower thorax demarcated by the xiphoid process and 10th rib. A 3-dimensional motion analyzer measured the difference in volume within the upper and lower hemithoraces through change of movement of the markers. For calculation of thoracic volume, 6 imaginary hexahedra were visualized for the upper thorax and lower thorax. Each imaginary hexahedron was divided into 3 imaginary triangular pyramids to calculate positional vectors using data obtained from each marker's position. Finally, volume for the hexahedra and triangular pyramids was calculated. To measure for changes in right and left hemithoraces' volume imaginary midpoints were established between the ventral and dorsal markers. The upper and lower thoraces encompassed the anterior and posterior spaces between the ventral and dorsal markers and their respective midpoints. Bunkyo Gakuin University Medical Ethics Review Board approved this study (No. 2016-0024).

Results:

For all participants in stooped sitting for both breathing patterns, the left upper hemithorax showed significantly greater change in upper thoracic volume and significantly greater change in thoracic configuration on termination of inspiration and expiration. For the healthy men, the left lower hemithorax showed significantly greater change in thoracic configuration and lower thoracic volume on termination of inspiration and expiration. For the patient in the right lower hemithorax, there was a significantly greater change in thoracic configuration and lower thoracic volume on termination of inspiration and expiration for both breathing patterns.

Conclusions:

Correction of stooped posture may facilitate an improvement in breathing.

Disclosures:

None.