Influence of Kyphosis on Chest Wall Motion

-Comparison of Slump Sitting and Straight Sitting-

Abstract

[Purpose] To clarify whether kyphosis affects respiratory function, we measured the chest wall motion during respiration in two sitting postures using a 3-D motion analyzer. [Subjects and Method] Subjects (14 healthy males) were seated in two positions: straight sitting as the control, and slump sitting with an angle of 10 degrees backward to the pelvis. We measured chest wall motion at the time of a respiration as the amount of displacement of reflecting markers on the chest wall, and compared the motion in the two postures. [Results] The chest wall motions in slump sitting were significantly smaller than those in straight sitting, based on the motions of the markers. [Conclusion] Apparently, kyphosis restricts the expansion movement of the upper thorax during inspiration. This result suggests that kyphosis is involved in elements of ventilatory impairment.