Effect of repeated reclining movements on the back support of the electric reclining chair on pelvic tilt angle and respiratory function

Abstract

This study investigated the effects of repeated reclining movement, such as inclining and raising the back support, on pelvic tilt angle and respiratory function. The subjects were 21 healthy adults (20.6±0.6 years old). We measured pelvic tilt angle and forced vital capacity (FVC) before and after reclining movement in two experimental conditions: one condition with one reclining movement and the other condition with three reclining movements. In both conditions, the pelvis tilted significantly backward (p＜0.01) and FVC significantly decreased (p＜0.05) after the reclining compared with before the reclining. In the three-time condition, the pelvis tilted significantly backward compared to the one-time condition (p＜0.01), but there was no significant difference in FVC in comparison with the one-time condition. The results suggest that repetition of reclining movement increases posterior pelvic tilt, but the decrease in FVC may be caused by effects other than increase of posterior pelvic tilt.