Effect of the trunk forward bending angle in sitting position on slow vital capacity

[Purpose] The purpose of this study was to examine whether a trunk forward bending angle in sitting position affected slow vital capacity (SVC). [Subjects and Methods] The subjects of this study were 18 healthy college students to whom the study’s methods and purpose were explained and their agreement for participation was obtained. Slow vital capacity was measured using spirometry (Pony FX, COSMED Inc., Italy), repeatedly at a body bending angle of 0°, 15°, and 30° in the sitting position. [Results] Vital capacity, expiratory reserve volume, and inspiratory reserve volume were significantly different according to the trunk forward bending angle. There were no statistically significant differences in tidal volume and inspiratory capacity. [Conclusion] The results demonstrated that the body bending angle of 15° in the sitting position was the most effective angle for increasing lung volume.